I'm not entirely sure but it should be (3/5) together. For pen the probability is (5/20) and for crayon is (12/20) add them equals (12/20) simply equals (3/5) HOPE IT HELPS
The first equation is x = -1
The second and third equations are no solution
The third equation is all rel numbers.
We can tell each one by solving them. In the first one, you get the following.
4 + x = -8x - 5 ----> Add 8x to both sides
4 + 9x = -5 ----> Subtract 4 from both sides
9x = -9 ----> Divide both sides by 9
x = -1
For the middle two, when you attempt to solve, you get untrue statements. This shows there are no solutions. See the example below.
7 + 2x = 2x - 7 ----> Subtract 2x from both sides
7 = -7 (UNTRUE)
And for the last one, each term cancels out, which shows that we have all real solutions.
-3x + 3 = 3( 1 - x) ----> Distribute the 3
-3x + 3 = 3 - 3x ----> Add 3x to both sides
3 = 3 (TRUE)
Volume of a triangular prism = base area x height
720 = base area x 5
base area = 720 ÷ 5 = 144 ft²
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Answer: The base area is 144 ft²
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