Let x = width
<span>length is 8 cm more than three times it’s width so length = 3x + 8
</span>
Perimeter of a rectangle = 2(L + W)
so
128 = 2(x + 3x + 8) solve for x (width)
128 = 2(4x + 8)
64 = 4x + 8
4x = 56
x = 14
width = 14 cm
length = 3(14) + 8 = 50 cm
Answer:
width = 14 cm
length = 50 cm
Answer:
the answer should be x=10
Answer:
B) 120
Step-by-step explanation:
m = miles
$98=$80+$0.15m
$98-$80=$80-$80+$0.15m
$18=$0.15m
$18/$0.15=$0.15m/$0.15
120=m
Juliet drove 120 miles for $98.
(this is a good explanation, I guess)
We are given the following:
- parabola passes to both (1,0) and (0,1)
<span> - slope at x = 1 is 4 from the equation of the tangent line </span>
<span>First, we figure out the value of c or the y intercept, we use the second point (0, 1) and substitute to the equation of the parabola. W</span><span>hen x = 0, y = 1. So, c should be equal to 1. The</span><span> parabola is y = ax^2 + bx + 1 </span>
<span>Now, we can substitute the point (1,0) into the equation,
</span>0 = a(1)^2 + b(1) + 1
<span>0 = a + b + 1
a + b = -1 </span>
<span>The slope at x = 1 is equal to 4 which is equal to the first derivative of the equation.</span>
<span>We take the derivative of the equation ,
y = ax^2 + bx + 1</span>
<span>y' = 2ax + b
</span>
<span>x = 1, y' = 2
</span>4 = 2a(1) + b
<span>4 = 2a + b </span>
So, we have two equations and two unknowns,<span> </span>
<span>2a + b = 4 </span>
<span>a + b = -1
</span><span>
Solving simultaneously,
a = 5 </span>
<span>b = -6</span>
<span>Therefore, the eqution of the parabola is y = 5x^2 - 6x + 1 .</span>
Eileen is able to save 13% of her allowance each month.
