Answer:
£12
Step-by-step explanation:
9.60 = 80% times y.
9.60 = 0.8y
Then, divide each side by 0.8 to get the equation in shape to solve for y.
y = 9.60/0.8
y=12
<span>-2x^2 + 10x + 9 =0
multiply whole equation by -1
2x^2 -10x -9 =0
(sqrt2x)^2 -2(sqrt2x)(5/</span>sqrt2) -9=0
add (5/sqrt2)^2 on both sides
(sqrt2x)^2 -2(sqrt2x)(5/sqrt2) + (5/sqrt2)^2-9=(5/sqrt2)^2
a^2-2ab+b^2=(a-b)^2
(sqrt2x - 5/sqrt2)^2=(5/sqrt2)^2+9
(sqrt2x - 5/sqrt2)^2=21.5
taking squareroot on both sides
sqrt2x - 5/sqrt2 = +-4.64
so
sqrt2x - 5/sqrt2 = +4.64 or sqrt2x - 5/sqrt2 = -4.64
sqrt2x = 4.64 + 5/sqrt2 sqrt2x = -4.64 + 5/sqrt2
sqrt2x =8.18 sqrt2x = -1.1045
x=8.18/sqrt2 x= -1.1045/sqrt2
x=5.78 x=-0.781
Answer:
see explanation
Step-by-step explanation:
Given that y is inversely proportional to x then the equation relating them is
y =
← k is the constant of proportionality
To find k use the condition that y = 7, x = 9
k = yx = 7 × 9 = 63, thus
y =
← equation of proportion
When x = 21, then
y =
= 3
Hi,
Equation:

Multiplying two negatives equals a positive.

Now equation looks like:

Hope this helps.
r3t40