Question

16. 4a – 8 = 28

17. 5x – 2x = 15

18. 3(-4x + 7) = 57

19. 19 – 8x = x – 17

20. 5 + x÷8 = -4

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5 days 2022-12-30T20:59:36+00:00 2 Answers 0 views 0

17. -5
Step-by-step explanation:  16. 4a-8=28
add 8 to both sides to start to isolate the variable (a)
-8+8 cancels each other out
28+8=36
4a=36
to completely isolate the variable divide both sides by 4
4a÷4=a
36÷4=9
a=9
17. 2*x-5*x-(15)=0
Step by step solution :
STEP
1
:
Pulling out like terms
1.1     Pull out like factors :
-3x – 15  =   -3 • (x + 5)
Equation at the end of step
1
:
STEP
2
:
Equations which are never true:
2.1      Solve :    -3   =  0
This equation has no solution.
A a non-zero constant never equals zero.
Solving a Single Variable Equation:
2.2      Solve  :    x+5 = 0
Subtract  5  from both sides of the equation :
x = -5

2. The solution to each of the linear equations are;
16) a = 9
17) x = 5
18) x = -3
19) x = 4
20) x = 72

How to solve linear equations?

16) 4a – 8 = 28
Add 8 to both sides to get;
4a = 36
divide both sides by 4 to get;
a = 9
17) 5x – 2x = 15
3x = 15
divide both sides by 3 to get;
x = 5
18) 3(-4x + 7) = 57
Multiply out the bracket to get;
-12x + 21 = 57
-12x = 57 – 21
-12x = 36
divide both sides by -12 to get;
x = -3
19) 19 – 8x = x – 17
Rearrange to get;
x + 8x = 19 + 17
9x = 36
x = 36/9
x = 4
20) 5 + x÷8 = -4
x/8 = 5 + 4
x = 8 * 9
x = 72