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Do Now . Solve the following… 6 = x + 2 4 = q + 13 23 = b - 19. 5b = 145 -7y = 28 2/3q = 18 1/5x = 2/7. 2-2 Solving Two-Step Equations. Solving using two steps. Step 1: Always add or subtract Step 2: Always multiply or divide To solve, use these steps
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Do Now • Solve the following… • 6 = x + 2 • 4 = q + 13 • 23 = b - 19 • 5b = 145 • -7y = 28 • 2/3q = 18 • 1/5x = 2/7
Solving using two steps • Step 1: Always add or subtract • Step 2: Always multiply or divide • To solve, use these steps • Identify the operations and undo them using inverse operations
Examples • 2x + 3 =15 • Step 1: Need to subtract 3 since it is inverse of addition • 2x + 3 – 3 = 15 -3 • 2x = 12 • Step 2: Need to divide 12 by 2 since it is inverse of multiplication • 2x/2 = 12/2 • X = 6 • Check Answers by plugging in 2(6) + 3 = 15
5 = t/2 – 3 • Step 1: Add 3 to both sides since it is inverse of subtraction • 5 + 3 = t/s – 3 + 3 • 8 = t/2 • Step 2: Multiply by 2 on both sides since it is inverse of division • 8 x 2 = t/2 x 2
T=16 Check Answers by pulling in
Try on your own… • 2 + a/4 = -1 • 3n – 4 = 11 • 5x + 12 = -13 • 6 = m/7 - 3
You are making a bulletin board to advertise community service opportunities in you town. You plan to use half a sheet of paper for each ad. You need 5 sheets of construction paper for a title banner. You have 18 sheets of construction paper. How many ads can you make? Write an equation for this word problem. 1/2a + 5 = 18 Solve A = 26
Solve with two terms in the numerator Remember Steps Check Answers • X-7 = -12 3 • 6 = x – 2 4 • d – 3 = 6 5 • a + 10 = 4 2
Write and solve this word problem… Members of a car-sharing program pay a fee of $50 per month plus $7.65 for every hour they use a car. A member’s bill was $149.45 last month. How many hours did the customer use a car last month? Equation: $7.65h + 50 = $149.45 Solution: 13 hours