Question

1. simplify 2n×6+8n.

2. what are the factors of x²- 6x+9.
3. calculate the volume of a cylinder 8cm long and 3.5cm in diameter.
4. if 4 is added to 3 times a certain number, the result is 31. find the number.
5. calculate a²+b² if a+b = 8 and a-b = 6

Answer 1

Answer:1. 20n
2. x=3, x=3
3. 76,97cm^2
4. X=9
5. 52

Explanation:
1. 2n x 6 +8n
= 12n + 8n= 20n
2. x² - 6x + 9 = 0
x -3
x -3
(x-3)*(x-3)=0
x=3 , x=3
3. V=π*r^2*h
h=8cm
r=3,5/2=1,75
V= π * 1,75^2*h
4. 3X+4=31
3X=27
X=9
5. (a+b)^2=8^2
a²+ b²+2ab=64
ab=6
a²+ b²+12=64
a²+ b²=52