Answer:
- C) (x − 3)2 = 25
- C) Factor out 4 from 4x2 + 40x.
Step-by-step explanation:
1. Adding the square of half the x-coefficient to both sides of the equation will "complete the square." That square is 9, so the result on the right is 16+9 = 25. Only selection C matches.
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2. To complete the square, you want to be able to put the quadratic into the form a(x -h)^2 = -k. For the purpose, it is most convenient to first factor "a" from the given quadratic. Then you can determine "-h" to be half the x-coefficient inside the parentheses.
Here, that looks like ...
4(x² +10x) = 80 . . . . . . . . . . step 1: factor out 4
4(x² +10x +25) = 180 . . . . . add 25 inside parentheses and the same number (4·25) on the right side of the equation
4(x +5)² = 180 . . . . . . . . . . . written as a square
Answer:
3.7
Step-by-step explanation:
each tick represents .1 unit
Answer:
SA = 105 in^2
Step-by-step explanation:
To find surface area, find the area of all the shapes and add it all together. This shape has 4 triangle faces. They are all the same. So we can find one of them and times by 4.
Area of a triangle:
A = 1/2b•h
= 1/2• 5 • 8
= 1/2 • 40
= 20
One triangle has area 20, so times by 4 (bc four triangles)
4•20
= 80
Area of square 5•5
= 25
Add the areas:
80 + 25
= 105 sq in
