Answer:

Explanation:
3x + 4y = 11 ----------------------(1)
x = 15 - 7y ----------------------(2)
Put Eq. (2) in (1)
3(15 - 7y) + 4y = 11
45 - 21y + 4y = 11
45 - 17y = 11
Subtracting 45 to bot sides
-17y = 11 - 45
-17y = -34
Dividing both sides by -17
y = -34 / -17
y = 2
![\rule[225]{225}{2}](https://img.qammunity.org/2022/formulas/mathematics/high-school/3icqlwn6du2l5ygbr7z2lp6sjjralcpq09.png)
Put y = 2 in Eq. (2)
x = 15 - 7(2)
x = 15 - 14
x = 1
![\rule[225]{225}{2}](https://img.qammunity.org/2022/formulas/mathematics/high-school/3icqlwn6du2l5ygbr7z2lp6sjjralcpq09.png)
Solution Set = {x,y} = {1,2}
![\rule[225]{225}{2}](https://img.qammunity.org/2022/formulas/mathematics/high-school/3icqlwn6du2l5ygbr7z2lp6sjjralcpq09.png)
Hope this helped!
~AH1807