Answer:
C. None of the above.
Step-by-step explanation:
x − (−x) + y
x + x + y
= 2x + y.
3x=y
X+Y=20
5=x and 15=y are the answer. You can use elimination or substitution or guess and check!
<span>Simplifying
0x + 7 + 5x = 2x + 30 + 40
Anything times zero is zero.
0x + 7 + 5x = 2x + 30 + 40
Combine like terms: 0 + 7 = 7
7 + 5x = 2x + 30 + 40
Reorder the terms:
7 + 5x = 30 + 40 + 2x
Combine like terms: 30 + 40 = 70
7 + 5x = 70 + 2x
Solving
7 + 5x = 70 + 2x
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '-2x' to each side of the equation.
7 + 5x + -2x = 70 + 2x + -2x
Combine like terms: 5x + -2x = 3x
7 + 3x = 70 + 2x + -2x
Combine like terms: 2x + -2x = 0
7 + 3x = 70 + 0
7 + 3x = 70
Add '-7' to each side of the equation.
7 + -7 + 3x = 70 + -7
Combine like terms: 7 + -7 = 0
0 + 3x = 70 + -7
3x = 70 + -7
Combine like terms: 70 + -7 = 63
3x = 63
Divide each side by '3'.
x = 21
Simplifying
x = 21</span>
There are 18 crayons
Explanation:
1 whole = 12 crayon
1/2 of 12 is 6
12+6=18