X=number of pounds
y=cost of pound .
x+y=cost
Answer:
C. 11
Step-by-step explanation:
Substituting, we have ...
8{80, 19, 11} ?= 88
{640, 152, 88} ?= 88
The value from the set that makes the equation true is x = 11.
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<em>Alternate methods of solution (other than substitution)</em>
It can be easier to make use of your knowledge of factoring:
8x = 8·11
x = 11
Or to make use of your knowledge of numbers (place value):
8·10 = 80
so x will not be very different from 10.
2 - 2 x 3 + 3
= 2 - 6 + 3
= -4 + 3
= -1
Ok, first group x terms
f(x)=(x²+4x)-8
factor out quadratic coefient (no need but that's the step)
f(x)=1(x²+4x)-8
take 1/2 of the linear coefient and square it
4/2=2, (2)²=4
add positive and negative of it insides the parenthasees
f(x)=1(x²+4x+4-4)-8
factor perfect square
f(x)=1((x+2)²-4)-8
distribute
f(x)=1(x+2)²-4-8
f(x)=1(x+2)²-12
and, now if we wanted to find the x intercepts where f(x)=0 then
0=1(x+2)²-12
12=(x+2)²
+/-2√3=x+2
-2+/-2√3=x
x=-2+2√3 or -2-2√3
that is where the x intercept are
and completed square form is
f(x)=(x+2)²-12
