Question

if 12x+17y=70 and 14x-8y=26, then what is the value of x+y?

Answer 1

Applying elimination method:
12x +17y=70....(1)
14x-8y=26......(2)
2(7x-4y=13)
now multiplying by 17
17(7x-4y=13)
119x-68y=221

now multiplying (2) by 4:
4(12x+17y=70)
48x+68y=280

48 x + 68y=280
119x- 68y =221
=167x=501
x=3. and. y=2

so x+y=5