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:
4th option
Step-by-step explanation:
7x(8x² - 4y² + 3y - 5) ← multiply each term in the parenthesis by 7x
= 56x³ - 28xy² + 21xy - 35x
This is solved by breaking the equasion down.
2 { 5 [12 + 5 (500 - 100) + 399 ]}
2 { 5 [12 + 5 (400) + 399]}
2 { 5 [12 + 2000 + 399]}
2 { 5 [2411]}
2 {12055}
24110
Is this the answer you were looking for?
Answer:
The amount of steel used = 94.38 
Step-by-step explanation:
Height of the tank = 4.5 m.
Diameter of the tank = 4.2 m.
But,
radius = 
= 
radius = 2.1 m
Total surface area of a cylinder = 2
rh + 2

= 2
r(r + h)
= 2 x
x 2.1 (2.1 + 4.5)
= 44 x 0.3 (6.6)
= 87.12
Total surface area of a cylinder = 87.12 
Since
of the steel was wasted, then;
x 87.12 = 7.26 
Actual area of steel sheet used = 87.12 + 7.26
= 94.38 
Thus, 94.38
of steel was used in making the tank.
Answer:
x-axis
Step-by-step explanation: