tolong di bantu jabarin ya :) dan makasih yg td udh bantu

7. 3x-4y =22 | x2
7x+2y=6 |x4
Y di eliminasi
6x-8y = 44
28x+8y = 24

34x = 68
x = 2

3x-4y = 22
3.2-4y = 22
-4y = 22-6
y = 16/-4
y = -4

2x+y
= 2.2 + -4
= 4+ -4
= 0 (jawaban C)

8. x+y = 12
x+2y = 20
x di eliminasi
-y = -8
y = 8

x+y = 12
x = 12 - 8
x = 4

x+y = 12
(0,12) (12,0)

z = 30x+15y
= 30.12 + 15.0
= 360 (jawaban D)

9. (gof)(x) = (3x-2)^2 + 2(3x-2) + 5
= 9x^2 - 12x + 4 + 6x - 4 + 5
=9x^2 - 6x + 5 (jawaban A)

11. 3x+2y = 48.000 | x1
x+4y = 41.000 |x3
x dieliminasi

3x+2y = 48.000
3x+12y = 123.000

-10y = -75.000
y = 7.500

5y= 5(7500) = 37.500 (jawaban D)