F(9)
sub 9 forx
f(9)=5(9)-16
f(9)=45-16
f(9)=29
f(9)=29
Answer:
It will take nine years and four months for the refrigerator to pay for itself.
Step-by-step explanation:
The new refrigerator which costs $1200, saves the family 22% annually in energy cost.
Since the old refrigerator costs $580 to run, we want to determine how many years it will take for 22% of $580 per year to make $1200.
22% of $580
= 580 × 0.22
= 127.6
That is, it saved then $127.6 per year.
Now,
$1200/127.6
≈ 9.4
Which means, it will take 9 years and 4 months for the refrigerator to pay for itself.
21-7=14 is a relate subtraction problem
Answer:
FC = 27, QC = 18
Step-by-step explanation:
The centroid Q is
the way along CF , therefore, QF is half as long as CQ
Given FQ = 9, then
QC = 2 × 9 = 18
FC = FQ + QC = 9 + 18 = 27
Answer:
Heavenly, we need the forumula for the area of a triangle, do you know it?
Step-by-step explanation:
Area of a triangle is (1/2 ) * B*H
where B = base
H = height
then
A = 1/2* B * H
A is given to be 20
B = b
H = b+4
plug all those into the formula,
20 = (1/2)*b*(b+4)
use your algebra skillz :P
20 = 1/2 *(
+ 4b)
20*2 =
+ 4b
40 =
+ 4b
0 =
+ 4b-40
rewrite the above so it's in x format
+ 4x -40 = 0
use the quadratic formula to find x , and for our problem, remember that x represents the base, or b, but don't mix it up with the b in the quadatic fomula, with the b of the triangle, which is the base, they are differnt "b"s :P
X = (b±
) / 2*a
a = 1
b = 4
c = -40
x = (4±
) /2*1
x = ( 4±
) / 2
x = (4±
) / 2
x = (4±13.266499)/2
x= 2±6.633249
x = 2 + 6.633249 = 8.633
b= 8.633 cm