Given:
First side(A): 2B - 7
Second side(B): B
Third side(C): B + 4
Plug in values:
A + B + C = 80
2B - 7 + B + B + 4 = 80
If you look at the coefficients only, you can rewrite the equation like this:
2B + B + B - 7 + 4 = 80
This means that 4B - 7 + 4 = 80
=4B - 3 = 80
= 4B = 80 + 3
B = 83/4, so you can either write B as 83/4 or as 20.75.
Checking your work:
A: 2(20.75) - 7 = 34.5
B: 20.75
C: 4 + 20.75 = 24.75
34.5 + 20.75 + 24.75 = 80cm.
Hope this helped.
Answer:
A = 450 cm²
Step-by-step explanation:
Since the right triangle is isosceles then the 2 logs are congruent , both 30 cm and at right angles to each other.
The area (A ) of the triangle is calculated as
A =
bh ( b is the base and h the perpendicular height )
Here b = h = 30 , then
A =
× 30 × 30 =
× 900 = 450 cm²
The first and last choices are true.
Answer:
the unit rate for miles per gallons = 
Step-by-step explanation:
Let x be the unit rate for miles per gallon.
Given:
Jack drove 43.5 miles. He used 11 gallons of gasoline.
Find the unit rate for miles per gallon?
Jack used 11 gallons of gasoline for 43.5 miles.
11 gallons = 43.5 miles
The unit rate for miles per gallon is
unit rate of gallons = total miles divided by total used gallons of gasoline

Therefore, the unit rate for miles per gallons is 3.95 miles.