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Bellwork 9/20/18. Go to https://join.quizizz.com. 1.) x + 7 = 54 2.) -3 + d = -28. Recap of 1-step equations. * USE REVERSE PEMDAS*. 3.) 2x=18 4.) -24=8x. Recap of 2-step equations 7.) 3x -7 = 21 8.) -2x -4 = -12. 10.) -36 = 12 - x. Recap Distributive Property.
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Bellwork 9/20/18 Go to https://join.quizizz.com
1.) x + 7 = 54 2.) -3 + d = -28 Recap of 1-step equations *USE REVERSE PEMDAS*
Recap Distributive Property 12.) 14 = -2(2x+2) 11.) 3(x+1) = 10
Block 3 Bellwork 9/21/18https://join.Quizizz.com
ObjectivesThe student will be able to: • Solve equations involving combining like terms and the distributive property • solve equations with variables on both sides. 8.EE.C.7 Solve linear equations in one variable.
Recap of equations with combining like terms & the distributive property 8.EE.C.7.a
What are the “like terms” in this expression? w + y + 2w + 8 RECAP --combining like terms What does it mean to “combine like terms”?
2.) 9x+1- 4x Circle or box the like terms.
Combine like terms to simplify the expression 3.) 12k -3 +5k +11
Combine like terms to Solve for the variable: 4.) -2y + 7 -3y= -23
Equations with variables on both sides NOT A RECAP
1) Solve: 3x + 2 = 4x - 1 • You need to get the variables on one side of the equation. • It does not matter which variable you move. • Try to move the one that will keep your variable positive. • When in doubt, move the one on the right.
1) Solve 3x + 2 = 4x - 1 - 3x - 3x 2 = x - 1 + 1 + 1 3 = x 3(3) + 2 = 4(3) - 1 9 + 2 = 12 - 1 • Draw “the line” • Subtract 3x from both sides • Simplify • Add 1 to both sides • Simplify • Check your answer
2) Solve 8y - 9 = -3y + 2 + 3y + 3y 11y – 9 = 2 + 9 + 9 11y = 11 11 11 y = 1 8(1) - 9 = -3(1) + 2 • Draw “the line” • Add 3y to both sides • Simplify • Add 9 to both sides • Simplify • Divide both sides by 11 • Simplify • Check your answer
Answer Now What is the value of x if 3 - 4x = 18 + x? • -3 • 3
3) Solve 4 = 7x - 3x 4 = 4x 4 4 1 = x 4 = 7(1) - 3(1) • Draw “the river” – Notice the variables are on the same side! • Combine like terms • Divide both sides by 4 • Simplify • Check your answer
-7x + 21 = -7 - 21 - 21 -7x = -28 -7 -7 x = 4 -7(4 - 3) = -7 -7(1) = -7 • Draw “the river” • Distribute • Subtract 21 from both sides • Simplify • Divide both sides by -7 • Simplify • Check your answer 4) Solve -7(x - 3) = -7
Answer Now What is the value of x if 3(x + 4) = 2(x - 1)? • -14 • -13 • 13 • 14
5) Solve • Draw “the river” • Clear the fraction – multiply each term by the LCD • Simplify • Add 2x to both sides • Simplify • Add 6 to both sides • Simplify • Divide both sides by 6 • Simplify • Check your answer 3 - 2x = 4x – 6 + 2x +2x 3 = 6x – 6 + 6 + 6 9 = 6x 6 6 or 1.5 = x
Special Case #1 6) 2x + 5 = 2x - 3 -2x -2x 5 = -3 This is never true! No solution • Draw “the river” • Subtract 2x from both sides • Simplify
Special Case #2 7) 3(x + 1) - 5 = 3x - 2 3x + 3 – 5 = 3x - 2 3x - 2 = 3x – 2 -3x -3x -2 = -2 This is always true! Infinite solutions or identity • Draw “the river” • Distribute • Combine like terms • Subtract 3x from both sides • Simplify
Answer Now What is the value of x if -3 + 12x = 12x - 3? • 0 • 4 • No solution • Infinite solutions
Answer Now Challenge! What is the value of x if -8(x + 1) + 3(x - 2) = -3x + 2? • -8 • -2 • 2 • 8