Answer:
80 cm^3 (cm cubed)
Step-by-step explanation:
5 x 2 x 8
18. s = 5r^2 + 7......making r the subject
s - 7 = 5r^2
(s - 7) / 5 = r^2...by taking the sqrt of both sides, it eliminates the ^2
( sqrt (s-7)/5) = r
19. h = ut - 1/2gt^2....u = 100, t = 1 4/5(or 9/5)...g = 6.4
h = (100)(9/5) - 1/2(6.4)(9/5^2)
h = 180 - 1/2(6.4)(3.24)
h = 180 - 3.2(3.24)
h = 180 - 10.368
h = 169.632 or 169 79/125
20. sorry..do not know this one
Answer:
B.
Step-by-step explanation:
Both equations use x squared
He bought 3 small notebooks (3*7=21) and 3 large notebooks (3*10=30)
21+30=51
Answer:

Step-by-step explanation:
A quadratic equation has one root if the discriminant is 0.
That is we need
for this particular question.
Compare the following to find
:


The variable
is representative of the variable
here.



Plug in into
:


Subtract 4 on both sides:

Divide both sides by 16:

Reduce:
