Let's call the younger student's age A and the older student's age B. The teacher's age will be T.
B = 2A
T = 5B
T+5 = 5(A+5)
Simplify the last equation.
T+5 = 5A+25
T = 5A+20
Now we have two equations solved for T, so we can set them equal to each other.
5B = 5A + 20
We can plug 2A in for B
5(2A) = 5A + 20
10A = 5A + 20
5A = 20
A = 4
To find T, we plug 4 in for A in T = 5A + 20
T = 5(4) + 20
T = 40
The answer is 40 years old.
Answer:
D. 11.8 cm
Step-by-step explanation:
This triangle is a 30°-60°-90° triangle. There is a shortcut to find the lengths of the sides of a 30°-60°-90° triangle. The longest side is the hypotenuse. The longest side is double the shortest side or, the shortest side is half the longest side. Here the longest side is 5, so the short leg (shortest side) is 2.5
The other shortcut is that the longer leg is the
short leg×sqroot3
Here, the short leg is 2.5, so the long leg is 2.5×sqroot3
Perimeter is all the sides added together.
5 + 2.5+ 2.5×sqrt3
Do the times first.
5 + 2.5 + 4.3
= 11.8
Square root each side
x-5=positive/negative 9
x=14, and -4
There are 39 boys.
First you divide 4 into 52 because there are 3 boys for 4 girls.
Then you take the quotient, 13, and multiply by 3.
