Answer:
r = 16
Step-by-step explanation:
Cross multiply:
4 x 20 = r x 5
Simplifying
4 x 20 = r x 5
Multiply 4 x 20
80 = r x 5
Reorder the terms for easier multiplication:
80 = 5r
Solve
80 = 5r
Solve for variable 'r'.
Move all terms containing r to the left, all other terms to the right.
Add '-5r' to each side of the equation.
80 + -5r = 5r + -5r
Combine like terms: 5r + -5r = 0
80 + -5r = 0
Add '-80' to each side of the equation.
80 + -80 + -5r = 0 + -80
Combine like terms: 80 + -80 = 0
0 + -5r = 0 + -80
-5r = 0 + -80
Combine like terms: 0 + -80 = -80
-5r = -80
Divide each side by '-5'.
r = 16
Simplify
r = 16
Answer:
Step-by-step explanation:
Notice that they are asking you to write the equation of the parabola in vertex form, that is using the coordinates of the vertex 
in the expression:
we can start by directly replacing the given vertex coordinates (-3, -3) in the expression, and then using the extra info on the point the parabola goes through in order to find the parameter 
:
So, now we can write the full expression for the parabola:
Answer:
< then >
Step-by-step explanation:
11 7/8 can be written as (11 + 7/8). If we find (11+7/8)², we know that √(11+7/8)² = (11+7/8), so we can compare (11+7/8)² with 129 and see which is bigger.
(11+7/8)² = (11+7/8) * (11+7/8)
= 121 + 7/8 * 11 + 7/8 * 11 + (7/8)²
= 121 + 77/8 + 77/8 + (7/8)²
77/8 is greater than 9 (8*9 = 72) but less than 10 (8*10=80). Rounding down to 7, we have
121 + 7 + 7 + (7/8)²
= 135 + (7/8)²
Even when rounding down, (11+7/8)² is greater than 129. Therefore,
129 < (11+7/8)²
square root both sides
√129 < (11+7/8)
We can apply a similar process for the next one.
(3+5/6)² = (3+5/6) * (3+5/6)
= 9 + 5/6 * 3 + 5/6 * 3 + (5/6)²
= 9 + 15/6 + 15/6 + (5/6)²
15/6 is less than 3 (6*3 = 18) but greater than 2 (6*2 = 12). Rounding down to 2, we have
9 + 2 + 2 + (5/6)²
= 13 + (5/6)² > 10
Even when rounding down, (3+5/6)² is greater than 10
(3+5/6)² > 10
square root both sides
(3+5/6) > √10
