$\begin{cases} x=-5\implies &x+5=0\\ x=3\implies &x-3=0 \end{cases}\qquad \implies \underline{a(x+5)(x-3)~~ = ~~\stackrel{0}{y}} \\\\\\ \stackrel{\textit{we also know that}}{P(0)=-30}\implies \begin{cases} x=0\\ y=-30 \end{cases}\implies a(0+5)(0-3)~~ = ~~-30 \\\\\\ a(5)(-3)=-30\implies -15a=-30\implies a=\cfrac{-30}{-15}\implies \boxed{a=2} \\\\[-0.35em] ~\dotfill\\\\ 2(x+5)(x-3)=y\implies 2(\stackrel{F~O~I~L}{x^2+2x-15})=y\implies \underline{2x^2+4x-30=y}$

Check the picture below.

8 0

3 years ago

Beth has dimes and quarters worth $3.70. if there are 19 coins in all, how many quarters does she have

myrzilka [38]

You can set this up as a system of equations.

x + y = 19
10x + 25y = 3.70

Your answer would be 31.42 dimes and -12.42 quarters.

4 0

3 years ago

Add. Answer as a fraction. Do not include spaces in your answer. Do not include spaces in your answer.

skad [1K]

Answer: 49/9

Step-by-step explanation: 42/9 + 7/9 = 49/9

Make first fraction into improper fraction with the same common dominator as 7/9 and add them both

Hope this helps:)

7 0

3 years ago

A triangle has a base 9cm and a perpendicular height 4.7 cm. work out the area of the triangle​

A triangle has a base 9cm and a perpendicular height 4.7 cm. work out the area of the triangle