Answer:
Step-by-step explanation:
The starting equation is
12-(3x+13)=0
First add 3x+13 to both sides so that only 12 is on the left
12=3x+13
now subtract 13 from both sides to isolate your variable
-1=3x
Finally divide both sides by 3 to get your final answer
x=-1/3
Answer:
C. 61
Step-by-step explanation:
Two sides are equal, so the triangle is an isosceles triangle.
Both base angles are equal.
Angles in a triangle add up to 180 degrees.
58 + x + x = 180
58 + 2x = 180
2x = 122
x = 61
Answer:
54
Step-by-step explanation:
9/12=x/12
9*12=108
108/2=54
since this is a multiplication, all the numerators are just factors of the product numerator and all denominators are just factors of the product denominator, so we can simply reorder them some, without changing the product.

If you want to easily find the solution you can use your calculator.
Just divide 77 by 110 and see the result.
77/110 = 0.7 = 7/10 = 70/100 = 70%
100% - 70% = 30%
Explanation
110*x=77
x=77/110, but the answer is not a percent
So 77/110 = ?/100 => ?=77*100/110=70 => 70%
But since 70% does not represent a percentage decreasement, we need to subtract it from the 100%
100% - 70% = 30%