add them together then divide by 5
81 +86 +81 +76 +71 = 395
395/5 = 79
your average was 79
<span>3(x + 5) = 2(3x + 18)
Use the distributive property:
3(x)+5(3)=2(3x)+18(2)
Simplify:
3x+15=6x+36
6x+36=3x+15
3x+36=15
3x=-21
x=-7
Check answer:
3(-7+5)=2(-21+18)
3(-2)=2(-3)
-6=-6
Hope this helps :)
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Let's call that number x, twice the number will be 2x, sum of it and 5 is, 2x+5. So if this expression is at most 15, it means, it can be only less than 15 and equal to 15. Let's show this as an inequality.
Let's solve.
![x\quad \in \quad \left[ -\infty ,5 \right]](https://tex.z-dn.net/?f=x%5Cquad%20%5Cin%20%5Cquad%20%5Cleft%5B%20-%5Cinfty%20%2C5%20%5Cright%5D%20)
If the number is a natural number. The values it can take is,
![x\quad \in \quad \left[ 0,1,2,3,4,5 \right]](https://tex.z-dn.net/?f=x%5Cquad%20%5Cin%20%5Cquad%20%5Cleft%5B%200%2C1%2C2%2C3%2C4%2C5%20%5Cright%5D%20)
To find the probability of landing on a triangle, you will want find the combined areas of the triangles and the total area of the square target.
Divide the area of the combined areas and the total area to find the probability of landing on a triangle.
A = 1/2bh
1/2 x 8 x 8
A = 32 square inches
32 x 4
128 square inches (areas of triangles)
A = bh
26 x 26
A = 676 square inches
128/676 = 0.189
There is an approximate probability of 0.19 of hitting a triangle.
