Y =ax² + bx +c
1) Point (0,7)
7 = a*0² +b*0 +c
c = 7
y=ax² + bx + 7
2) Point (1,4)
4=a*1² + b*1 + 7, ----> 4 = a +b + 7, ------>
a+b= - 3
3) Point (2, 5)
5=a*2² + b*2 + 7, ----> 5=4a+2b +7,---> -2=4a+2b, ---->
-1=2a + b
4)
a+b= - 3, ----> b= -3 - a (substitute in the second equation)
2a+b= -1
2a - 3 - a = -1, ----> a - 3 = -1,
a =2
5) a+b= - 3
2 + b = -3
b = -5
y=2x² - 5x + 7
Answer:
12°
Step-by-step explanation:
Let's start with the easy first.
We know that m∠C is 39° because together ∠C and the exterior angle equal 180°. And 180 - 141 = 39.
Now, we can use this to find the remaining two angles.
180° - 39° = 141°
So, this means that we can set up m∠A + m∠B = 141°.
6x + 9 + x - 8 = 141
7x + 1 = 141
7x = 140
x = 20
Finally, we can plug in for our x value and find m∠B.
m∠B = x - 8
m∠B = 20 - 8
m∠B = 12°
Answer:
how this helps
Step-by-step explanation:
Answer: C. (-7x+9)(x-2)
Step-by-step explanation:
1. Factor out the negative sign.
−(7x^2+5x−18)
2. Split the second term in 7x2+5x−18 into two terms.
−(7x^2+14x−9x−18)
3, Factor out common terms in the first two terms, then in the last two terms.
−(7x(x+2)−9(x+2))
4. Factor out the common term x+2x+2x+2.
−(x+2)(7x−9) or (-7x+9)(x-2)