Very complex, you should ask each individual question, or give more points
general strategy:
get 1 side to equal 0
factor
set each factor to 0
solve
1. factor out the x and set each to zero
x(x+7)=0
x=0
x+7=0
subtract 7
x=-7
x=0 or -7
2. factor out the 6s
6s(s+3)=0
6s=0
s=0
s+3=0
subtract 3
s=-3
s=-3 or 0
3. I'm assuming that the equation was supposed to be t^2+8t+16 so
find what 2 numbers multiply to get 16 and add to get 8
the numbers are 4 and 4
factor
(x+4)(x+4)=0
x+4=0
subtract 4
x=-4
4. find what 2 numbers multipy to get 25 and add to get -10
the numbers are -5 and -5
factor
(x-5)(x-5)=0
set each to zero
x-5=0
add 5
x=5
5. subtract 16 from both sides
h^2+6h-16=0
find what 2 numbers multiply to get -16 and add to get 6
the numbers are -6 and 10
factor
(h-6)(h+10)=0
set each to zero
h-6=0
add 6
h=6
h+10=0
subtract 10
h=-10
h=-10 or 6
6.subtract 5x from both sides
x^2-5x-14=0
find what 2 numbers multiply to get -14 and add to get -5
the numbers are -7 and 2
factor
(x-7)(x+2)=0
set each to zero
x-7=0
add 7
x=7
x+2=0
subtract 2
x=-2
x=-2 or 7
7.add 2r^2 to both sides
2r^2+11r+15=0
difficult so multiply 2 and 15 and get 30
not factor and find what 2 numbers multiply to get 30 and add to get 11
the numbers are 5 nd 6
split 11 up into 5 and 6
2r^2+6r+5r+15=0
group and factor
(2r^2+6r)+(5r+15)=0
factor
2r(r+3)+5(r+3)=0
reverse distribute
(2r+5)(r+3)=0
set each to zero
2r+5=0
subtract 5
2r=-5
divide 2
r=-5/2
r+3=0
subtract 3
r=-3
r=-3 or -5/2
8. this is a difference of 2 perfect squares in which if you have
x^2-y^2 that factors out of (x-y)(x+y) so
x^2-25=0
x^2-5^2=0
(x-5)(x+5)=0
set each to zero
x-5=0
add 5
x=5
x+5=0
subtract 5
x=-5
x=-5 or 5
9. differnce of 2 perfect squares
81-4x^2=0
9^2-(2x)^2=0
(9-2x)(9+2x)=0
set each to zero
9-2x=0
add 2x to both sides
9=2x
divde 2
9/2=x
9+2x=0
subtract 9 from both sidees
2x=-9
divide 2
x=-9/2
x=-9/2 or 9/2
10. subtract 12s from both sides
4s^2-12s+9=0
multiply 4 and 9 and get 36
find what 2 numbers multiply to get 36 and add to get -12
the numbers are -6 and -6
split up the -12s into -6s and -6s
4s^2-6s-6s+9=0
group
(4s^2-6s)+(-6s+9)=0
factor
2s(2s-3)+(-3)(2s-3)=0
reverse distribute
(2s-3)(2s-3)=0
set each to zero
2s-3=0
add 3
2s=3
divide 2
s=3/2
ANWERS:
1. x=0 or -7
2. s=-3 or 0
3. x=-4
4. x=5
5. h=-10 or 6
6. x=-2 or 7
7. r=-3 or -5/2
8. x=-5 or 5
9. x=-9/2 or 9/2
10. s=3/2
I want to talk about X's. I'll start by talking about this X - a cross (photo 1). Specifically, a cross made of two perpendicular lines - lines that meet each other at right angles all around. What's special about a cross? There's the religious significance, but in our case, there's also the <em>symmetry</em>. The quick, intuitive definition of symmetry is some quality that a thing has where, if you do something to it, it'll still look the same. Your body is symmetric; the left side of our bodies looks like we took the right side and flipped it - they're mirror images of each other.
One of the symmetries of this cross is right here. (Picture 2) It splits the cross into <em>two identical halves</em>, one a mirror image of the other. Most importantly, <em>the angles on each side of the line are identical</em>. We can draw this same mirror into our problem, too (picture 3). This symmetry tells us that those two unknown angles are exactly the same - <em>equal</em>. So, if angle MNJ is 5x+2 and angle LNK is 3(x+14), we now know that
5x + 2 = 3(x + 14), or, getting our algebra sorted:
5x + 2 = 3x + 42
2x = 40
x = 20
Now that we know x, we can find MNJ - which, because X's are symmetric, is exactly the same angle as LNK. Crunching the numbers, we find
m∠MNJ = m∠LNK = 5(20) + 2 = 100 + 2 = 102°.
Side note: the technical term for pairs of angles like MNJ and LNK is vertical angles. What we've shown here is, because of the symmetry of intersecting lines, vertical angles are always equal.
Answer: nina is getting $15 for 1 lawn.
Step-by-step explanation:
1 $15
2 $30
3 $45
4 $60
Answer:
Step-by-step explanation:
Given the expressions :
The list price of the item is 80 percent of the original price. The price of the item has been reduced by 80 percent.
Write a pair of linear equations using variables of your choice to prove that these two statements are not equivalent.
Let the original price = x
Expression 1 : The list price of the item is 80 percent of the original price
List price = 80% of x
List price = 0.8x
Expression 2: The price of the item has been reduced by 80 percent
Price = x - 80% of x
Price = x - 0.8x
Price = 0.2x
Multiply by percentages is different from an Incremental or decrement in percentage. The first expression above signifies a direct multiplication by the stated percentage while the second signifies a decrease in price based on a certain percentage of the original price.
Wording of percentages are so important for clarity in other to understand if the statement signifies a direct application of the percentage prescribed or a change in quantity, amount or size relative to the base unit.
There you good luck with everything
