Question

12. If x= 20 - b, y = a +5b, then calculate the following: a 2x+3y b. 4x - 5y ​

Answer 1

1. 2x+3y

= 2(20 - b) + 3(a + 5b)

= 40 - 2b + 3a + 15b

= 3a + 13b + 40 (ans.)

2. 4x - 5y

= 4(20 - b) + 5(a + 5b)

= 80 - 4b + 5a + 25b

= 5a - 4b + 80 (ans.)