Question

Please help i dont understand ​

Answer 1

Answer :

1) If x = 6

Substitute 6 for x in the expression.

a) 5x-9

5(6)-9

30-9

21

b) 2x-7

2(6) -7

12-7

5

c) 8x+5

8(6)+5

48+5

53

d) 4(x+3)

4(6+3)

4(9)

36

e) x²-(-4)

6²-(-4)

36+4

40

f) 3x²+1

3(6²)+1

3(36) +1

108+1

109

2) Solve

a) 54 = 3x

Divide both sides by 3.

54/3 = 3x/3

x = 18

b) x-9 = -3

Add 9 to both sides.

x-9+9 = -3+9

x = 6

c) x/7 = 140

Express the 140 over 1 and cross multiply.

x/7 = 140/1

x = 140×7

x = 980

d) x/8 = 72

Express the 72 over 1 and cross multiply.

x/8 =72/1

x = 72×8

x = 576