150 likes | 1.13k Views
Problems in linear equations. St. Angela ( Group 5). 1 st proble m. 1 st problem. Paula is now 18 years old and her colleague Monica is now 14 years old. How many years ago was Paula twice as old as Monica?. Chart. Solution. (18-x) - 2(14-x) 18-x = 28-2x. answer. X = 10.
E N D
Problems in linear equations St. Angela ( Group 5)
1st problem • Paula is now 18 years old and her colleague Monica is now 14 years old. How many years ago was Paula twice as old as Monica?
Solution • (18-x) - 2(14-x) • 18-x = 28-2x
answer • X = 10
2nd problem • A triangular Pyramid with a square base has a height equal to two times the side of it’s base. Find the dimension of the Pyramid if the volume is 100 cu. cm
Solution • Height = 2 • Side of the base = x • NOTE = Volume of the pyramid = 1/3 ( Area of the base) x height • 100 = 1/3 (x^2)(2x) • 100 = 2/3 (x^3) • X = cube root of 150 • Height = 2x • 2( cube root of 150)
Answer • Height = 2 cube root of 150 • Side of base = cube root of 150
3rd problem • JJ is three times older as Jan-Jan. Three years ago, JJ was four times as old as Jan-Jan. the sum of there age is?
solution • 3x-3 = 4(x-3) • 3x-3 = 4x-12 • X-12 = 3 • x = Jan- Jan’s age • 3x = 27 ( JJ’s age )
answers • Sum of ages = 9 + 27 • = 36