The third choice, 4x²+18x+0.25=0, is correct.
The frame will have the same thickness on both sides of the mirror. Therefore we add 5+x+x to get the total length, and we have 4+x+x to get the total width.
The area is found by multiplying the total width and total length:
A=(5+x+x)(4+x+x)
A=(5+2x)(4+2x)
Multiplying the binomials, we have:
A=5*4+5*2x+2x*4+2x*2x
A=20+10x+8x+4x²
A=20+18x+4x²
We know that the area is 19.75:
19.75=20+18x+4x²
We need quadratics set equal to 0, so subtract 19.75 from each side:
19.75-19.75 = 20+18x+4x²-19.75
0=0.25+18x+4x²
In standard form, it will be:
4x²+18x+0.25=0
Isaiah will mow 9 lawns in 3 hours at the given rate.
Step-by-step explanation:
Given,
Lawns mowed in 25 hours = 75 lawns
We will find unit rate in terms of lawns;
75 lawns = 25 hours
1 lawn =
9 lawns =
9 lawns = 3 hours
Isaiah will mow 9 lawns in 3 hours at the given rate.
Keywords: unit rate, fraction
Learn more about fractions at:
#LearnwithBrainly
Answer:
503634
Step-by-step explanation:
The formula for calculating future value:
FV = P (1 + r) n
FV = Future value
P = Present value
R = interest rate
N = number of years
200,000(1.08)^12
1/52, as there is only 1 ace of hearts in a standard deck (no jokers) of 52 cards.
Step-by-step explanation:
x - 4 = 2x + 9
x - (2x) = 9 + (4)
-x = 13
x = -13.