Answer:
Step-by-step explanation:So we know x + y = 21 and 5x +10y = 165 We line them up in columns x + y = 21 5x +10y = 165 To eliminate the x variable, I'll multiply every element in the 1st equation by -5. -5x + -5y = -105 5x + 10y = 165 Now we combine (add) the equations, which eliminates x altogether. 5y = 60 ... y = 12 From there, x + 12 = 21 ... x = 21-12 ... x = 9 You should double check. Do 9 nickles and 12 dimes equal $1.65? A very important thing to remember using this method is to do the same thing to each element in the equation that you change! I hope that helps.
Answer:
40
mark me brainlist ok ôókk
Answer:
it's 2 because it's the smallest number
Answer:
A
Step-by-step explanation:
Given the zeros are x = - 1 and x = 3 then the factors are
(x + 1) and (x - 3) and the parabola is the product of the factors, that is
y = a(x + 1)(x - 3) ← where a is a multiplier
To find a substitute (0, - 9) into the equation
- 9 = a(0 + 1)(0 - 3) = a(1)(- 3) = - 3a ( divide both sides by - 3 )
3 = a, thus
y = 3(x + 1)(x - 3) ← expand the factors using FOIL
= 3(x² - 2x - 3) ← distribute by 3
= 3x² - 6x - 9 → A
I think 12 percent but sorry if I got it super wrong
