Question

if X=a+2b and y=a-2b, find (3x+4y)-(5x-7y) in terms of a and b​

Answer 1

Answer:

x= a+2b ,y= a-2b

3(a+2b)+4(a-2b)

⇒3a+6b+4a-8b

⇒7a-2b                  ---1

then 2nd eqn

5x-7y

⇒5(a+2b) -7(a-2b)

⇒5a+10b-7a+14b

⇒-2a+24b              ---2

now by solving eq 1  and 2

7a-2b-(2a+24b)=  7a-2b-2a-24b=5a-26b

Step-by-step explanation:

just put the value of x and y given in the eqn and solve it

Answer 2

•x=a+2b

•y=a -2b

•(3x+4y)-(5x-7y)

putting value:-

•(3(a+2b)+4(a- 2b))-(5(a+2b)-7(a- 2b))

•(3a+6b+4a-8b)-(5a+10b-7a+14b)

•(7a-2b)-(-2a+24b)

•7a-2b+2a-24b

•9a-26b