Question

If PR = 4x – 2 and RS = 3x – 5, which expression represents PS?

x – 7
x – 3
7x – 7
7x + 3

Answer 1

(4x-2)+(3x-5)=PS

4x-2+3x-5=PS

4x+3x-2-5 (just rearranging)

=7x-7

Answer: 7x-7 ( third choice)

Answer 2

PS = 7x-7

Explanation:

Given the two expression

PR = 4x – 2 and RS = 3x – 5,

Adding the two vectors PR+RS = PS

PS = (4x-2)+(3x-5)

Expanding the bracket will give;

PS = 4x-2+3x-5

Collecting the like terms

PS = 4x+3x-2-5

PS =7x-7

The expression that represent PS is 7x-7