Answer:
Step-by-step explanation:
4x+2y = -24 -------------(i)
<u> -4x+y = 12 -</u>------------(ii)
add (i) &(ii) 3y = -12
y = -12/3
y = -4
Put y = (-4) in (i)
4x + 2*(-4) = -24
4x - 8 = -24
4x = -24 + 8
4x = -16
x = -16/4
x = -4
Answer:
Step-by-step explanation:
The total amount Rita spent is ...
(18.54x +23) +(25) = 18.54x +48 . . . total spent
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When x=2, that is approximately ...
(18.5)(2) + 48 = 37 +48 = (40 -3) +(50 -2) = (40 +50) -(3 +2) = 90 -5 = 85
Rita spent about $85 if she bought 2 items.
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<em>Additional comment</em>
Estimation is often done using 1 significant figure. In this case, that would mean rounding the equation to 20x+50, so it would give a value of 90 when x=2.
An additional task when estimating is to estimate the error in the estimate. Here, using 20x+50 has an error of approximately 1.5x+2 (too high), so the error for 2 items will be about (1.5(2)+2) = 5. That is, the estimate of 90 is approximately 5 too high. Even this estimate has a remaining small error of 0.04x (too low).
Sometimes a diagram can be helpful. If x is the distance from the house to the parallel side of the fenced plot, then the total length of fence will be x + x + 30 (feet). Jane wants to find x such that this length is 100 (feet).
The appropriate equation is ...
... A. x + x + 30 = 100
Answer:
Area = 64pi, Circumfrence=2pi(8)
Step-by-step explanation:
