A-b=21
5a-2b=18
We can use substitution here. Take the first equation and solve for A. (Picking this one because it's easy)
a = 21+b
Plugin to the second equation:5(21+b)-2b=18
Simplify: 105 + 5b - 2b = 18
Simplify: 105 + 3b = 18
Subtract both sides: 3b = 18-105
Simplify: 3b = -87
Divide: b = -29
Plug back into the first: a=21+b
a = 21 - 29
a = -8
Option D
Well the difference of 12 and 4 is 12-4=8 8 times 5=40
Answer:
perimeter= p1+p2 +p3+p4=add all sides.
area =l×b=
(10m×14m)= 140m
Hello!

We can go through each equation to solve:
1.
x + 3 = 4(x - 1) + 2
Distribute the coefficient outside of the parenthesis:
x + 3 = 4(x) + 4(-1) + 2
Simplify:
x + 3 = 4x - 4 + 2
x + 3 = 4x - 2
Subtract x from both sides:
3 = 3x - 2
Add 2 to both sides:
5 = 3x
Divide both sides by 3:
5/3 = x. This is not the answer.
2.
2x - 8 = 7 - 3x
Add 3x to both sides:
5x - 8 = 7
Add 8 to both sides:
5x = 15
Divide both sides by 5:
5x/5 = 15/5
x = 3. This is an answer.
3.
3(x + 2) = 14 - x
Distribute:
3(x) + 3(2) = 14 - x
3x + 6 = 14 - x
Add x to both sides:
4x + 6 = 14
Subtract 6 from both sides:
4x = 8
Divide both sides by 4:
4x/4 = 8/4
x = 2. This is not an answer.
4.
4(x - 1) = x + 5
Distribute:
4x - 4 = x + 5
Subtract x from both sides:
3x - 4 = 5
Add 4 to both sides:
3x = 9
Divide both sides by 3:
3x/3 = 9/3
x = 3. This is an answer.
5.
5 - 2(x + 1) = x
Distribute:
5 - 2x - 2 = x
Simplify:
3 - 2x = x
Add 2x to both sides:
3 = 3x
Divide both sides by 3:
3/3 = 3x/3
x = 1. This is not an answer.
6.
6(x - 4) = 2x
Distribute:
6x - 24 = 2x
Subtract 6x from both sides:
-24 = -4x
Divide both sides by -4:
-24/(-4) = -4x/(-4)
x = 6. This is not an answer.
Answer:
d
Step-by-step explanation:
The closed circle on -6 means that x can equal 6 and the thick line to the right means that x can be greater than -6.