Answer:
y = 18 and x = -2
Step-by-step explanation:
y = x^2+bx+c To find the turning point, or vertex, of this parabola, we need to work out the values of the coefficients b and c. We are given two different solutions of the equation. First, (2, 0). Second, (0, -14). So we have a value (-14) for c. We can substitute that into our first equation to find b. We can now plug in our values for b and c into the equation to get its standard form. To find the vertex, we can convert this equation to vertex form by completing the square. Thus, the vertex is (4.5, –6.25). We can confirm the solution graphically Plugging in (2,0) :
y=x2+bx+c
0=(2)^2+b(2)+c
y=4+2b+c
-2b=4+c
b=-2+2c
Plugging in (0,−14) :
y=x2+bx+c
−14=(0)2+b(0)+c
−16=0+b+c
b=16−c
Now that we have two equations isolated for b , we can simply use substitution and solve for c . y=x2+bx+c 16 + 2 = y y = 18 and x = -2
Answer:
x=1/6
Step-by-step explanation:
3x+4=9x+3
isolate x
1=6x
1/6=x
-4x+2=9 would be the answer for this equation
Let's say the tv was 100$ . Reduced by 20% means the tv is now 100 - 20 = 80% of the original price.
0.8(100) = 80$
Reduced again; by 10% means that it is now 100-10 = 90% of the 80$
0.9(80) = 72$
sale price ÷ original price
72$ / 100$ = 0.72 which is 72% of the original price. Which is a mark down of:
100 - 72 = 28%
The new price is 28% lower than the original price.
