The formula for area of a trapezoid is

so you add up the bottom base (17) and the top base (3) to get 20.
you then take the sum of the bases (20) times the height (8) to get 160.
lastly, you take 160 ÷ 2 to get your final answer, which is 80 (:
<span>1/3(21-3a)=6-a
I simplified the equation to the form, which is simple to understand
<span>1/3(21-3a)=6-a
Simplifying:
<span> + 0.333333333333*(21-3a)=6-a
Reorder the terms in parentheses
<span>+(+7-1a)=6-a
Remove unnecessary parentheses
<span>+7-1a=+6-a
We move all terms containing a to the left and all other terms to the right.
<span>-1a+1a=+6-7
We simplify left and right side of the equation.
<span>a=-1
<span>0=-1
The left and right sides are not equal, therefore there is no solution. This equation is invalid
Hope this helped
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Both 8,15,17 and 15,20,25 will form a right triangle
If you need help with these types of problems just go into google and search Pythagorean theory silver and plug in 2/3 side lengths and if the outcome equals the third number, then that means that the side lengths make a right triangle
1 Convert 12\frac{2}{3}12
3
2
to improper fraction. Use this rule: a \frac{b}{c}=\frac{ac+b}{c}a
c
b
=
c
ac+b
\frac{12\times 3+2}{3}\times 3\frac{1}{4}
3
12×3+2
×3
4
1
2 Simplify 12\times 312×3 to 3636
\frac{36+2}{3}\times 3\frac{1}{4}
3
36+2
×3
4
1
3 Simplify 36+236+2 to 3838
\frac{38}{3}\times 3\frac{1}{4}
3
38
×3
4
1
4 Convert 3\frac{1}{4}3
4
1
to improper fraction. Use this rule: a \frac{b}{c}=\frac{ac+b}{c}a
c
b
=
c
ac+b
\frac{38}{3}\times \frac{3\times 4+1}{4}
3
38
×
4
3×4+1
5 Simplify 3\times 43×4 to 1212
\frac{38}{3}\times \frac{12+1}{4}
3
38
×
4
12+1
6 Simplify 12+112+1 to 1313
\frac{38}{3}\times \frac{13}{4}
3
38
×
4
13
7 Use this rule: \frac{a}{b}\times \frac{c}{d}=\frac{ac}{bd}
b
a
×
d
c
=
bd
ac
\frac{38\times 13}{3\times 4}
3×4
38×13
8 Simplify 38\times 1338×13 to 494494
\frac{494}{3\times 4}
3×4
494
9 Simplify 3\times 43×4 to 1212
\frac{494}{12}
12
494
10 Simplify
\frac{247}{6}
6
247
11 Convert to mixed fraction
41\frac{1}{6}41
6
1
41 and 1/6
First you want to find how many words she types per hour.
There are 60 minutes in 1 hour.
So multiply 70 words/min times 60 min/ 1 hr to cancel out the minutes.
You will get 4200 words / hr
Then multiply 4200 by 4 and 5
use * as multiplication symbol
4200 words/hr * 4 = 16,800 words/hr
4200 words/hr * 5 = 21,000 words/hr
She will type 16,800 - 21,000 words/hr
So Your answer is going to be letter G