Answer:
Quadratic Equation | Factoring
Solve each quadratic equation using factoring.
1) v² + 5v + 6 = 0
doing middle term factorisation
v²+(3+2)v+6=0
v²+3v+2v+6=0
v(v+3)+2(v+3)=0
(v+3)(v+2)=0
either
<u>v=-3</u>
<u>or</u>
<u>v=-2</u>
2) g² - 3g = 4
keeping all terms in one side
g²-3g-4=0
doing middle term factorisation
g²-(4-1)g-4=0
g²-4g+g-4=0
g(g-4)+1(g-4)=0
(g-4)(g+1)=0
either
<u>g=4</u>
<u>or</u>
<u>g=-1</u>
3)w² + 4w = 0
w(w+4)=0
either
<u>w=0</u>
<u>or</u>
<u>w=-4</u>
4) s² - 8s + 12 = 0
doing middle term factorisation
s²-(6+2)+12=0
s²-6s-2s+12=0
s(s-6)-2(s-6)=0
(s-6)(s-2)=0
either
<u>s=6</u>
<u>or</u>
<u>s=2</u>
5) x ²+ 2x - 35 = 0
doing middle term factorisation
x²+(7-5)x-35=0
x²+7x-5x-35=0
x(x+7)-5(x+7)=0
(x+7)(x-5)=0
either
<u>x=-7</u>
<u>or</u>
<u>x=5</u>
6) r(r + 2) = 99
opening bracket
r²+2r=99
keeping all terms in one side
r²+2r-99=0
r²+(11-9)r-99=0
r²+11r-9r-99=0
r(r+11)-9(r+11)=0
(r+11)(r-9)=0
either
<u>r=-11</u>
<u>or</u>
<u>r=9</u>
7)k(k-4)=-3
opening bracket
k²-4k=-3
keeping all terms in one side
k²-4k+3=0
k²-(3+1)k+3=0
k²-3k-k+3=0
k(k-3)-1(k-3)=0
(k-3)(k-1)=0
either
k=3
or
k=1
8)t²+ 3t + 2 = 0
doing middle term factorisation
t²+(2+1)t+2=0
t²+2t+t+2=0
t(t+2)+1(t+2)=0
(t+2)(t+1)=0
either
<u>t</u><u>=</u><u>-</u><u>2</u>
<u>or</u>
<u>t</u><u>=</u><u>-</u><u>1</u>
9)m ^ 2 - 81 = 0
m²=81
doing square root in both side

<u>m=±9</u>
<u>either</u>
<u>m</u><u>=</u><u>9</u>
<u>or</u>
<u>m</u><u>=</u><u>-</u><u>9</u>
10) h²- 17h + 70 = 0
doing middle term factorisation
h²-(10+7)h+70=0
h²-10h-7h+70=0
h(h-10)-7(h-10)=0
(h-10)(h-7)=0
either
<u>h</u><u>=</u><u>1</u><u>0</u>
<u>or</u>
<u>h</u><u>=</u><u>7</u>
Jamaal has 20 models of cars and planes. He has 3 times as many cars as planes. What is the ratio of cars to total models? Mutiply its what 20X20X20
Written in slope intercept form y=mx+b.......m is the slope.......b is the y intercept or where the line crosses the y axis
y=-2/3x - 4
Answer:
There are 26 purple marbles in the bag.
Step-by-step explanation:
1) We have purple (p) and blue (b) marbles in a bag, and 41 marbles total so:
p+b = 41
2) we want to know how many purple marbles we have, so let's rearrange for p:
p = 41 - b
3) Our problem gives us an expression for the purple marbles in terms of the blue, let's write it using math symbols instead of words:
<em>"The number of purple marbles is 4 less than 2 times the number of blue marbles."</em>
so: p = 2b - 4
3) Now we're going to plug this in (or substitute it) for our p in our first equation, and solve for b
p = 41 - b
2b - 4 = 41 - b (substitution)
2b = 45 - b ( add 4 to both sides)
3b = 45 (add b to both sides)
b = 15 (divide both sides by 3)
4, last step!)
Now we know we have 15 blue marbles, that's great! But we still want to know how many purple marbles we have.
41- 15 = 26 purple marbles