Question

11. (x - 2)(x + 2) = 5;
12. (x + 3)(x - 3)=7
13. 3(2x + 3) - 5(7 - 4x) - 2(5x + 4) = -2
14. 8(4 - 3y) + 7(y - 3) + 3(9 + 7y) = 10
15. 6(z + 2) + 3(3z+ 7) = 4(5 + 4z) - 7
16. 5(12-t)-11(4t-5)=9(9-5t)-26

Answer 1

11. (x - 2)(x + 2) = 5

X²-4=5

X²=5+4

X²=9

x=±3

x1=-3, x=3

12.(x + 3)(x - 3)=7

x²-9=7

x²=7+9

x²=16

x=±4

x1=-4, x2=4

13. 3(2x + 3) - 5(7 - 4x) - 2(5x + 4) = -2

6x+9-35+20x-10x-8= -2

16x-34= -2

16x=-2+34

16x=32

x=2

14. 8(4 - 3y) + 7(y - 3) + 3(9 + 7y) = 10

32-24y+7y-21+27+21y=10

38+4y=10

4y=10-38

4y= -28

y= -7

15. 6(z + 2) + 3(3z+ 7) = 4(5 + 4z) - 7

6z+12+9z+21=20+16z-7

15z+33=13+16z

15z-16z=13-33

-z= -20

z=20

16. 5(12-t)-11(4t-5)=9(9-5t)-26

60-5t-44t+55=81-45t-26

115-49t=55-45t

-49t+45t=55-115

-4t= -60

t=15