Answer:
8
Step-by-step explanation:
Let's just call the number x for simplicity.
So, 7x is 8 less than x².
Putting this into an equation would look like this
x² - 8 = 7x
It looks like we'll have to factor this to solve. Before we do that we need to move the 7x to the left side so that everything is together.
x² - 7x -8 = 0
Now, we can proceed. To factor we first need to find the factors of -8.
The factors of -8 are
-2 ⋅ 4, -4 ⋅ 2, -1 ⋅ 8, 1 ⋅ -8.
We need to find the pair of factors that adds up to -7. The only ones that do are -1 and 8.
So now that we have these we can create a pair of binomials using them. This will give us the factored form of this equation.
( x + 1 ) ( x - 8 )
To find the solutions we will have to set them to 0 and solve each of these binomials individually.
x - 1 = 0
x = 1
So, one of the solutions is 1. It's not the one we want, since it's positive.
x - 8 = 0
x = 8
This is the one we want since it is positive.
Answer:
wilma is 22.5 mph
fred is 25.5 mph
Step-by-step explanation:
Time:40 minutes, or 2/3 hours
Speed:
Fred:x+3
Wilma: x
Distance:32 miles
2/3(x+x+3)=32
2/3(2x+3)=32
1 1/3x+2=32
4/3x=30
x=22.5
wilma is 22.5 mph
fred is 22.5+3= 25.5 mph
Answer:
134 children and 120 adult plates were served
Step-by-step explanation:
let the children mean be x
Let the adult meal be y
If fourteen less children’s meals were served than adult meals at a barbecue, then;
y = x - 14 .... 1
IF Children plate were 1.50 each and adult plates were 2.00 each with a total of 441 in amount then;
1.5x + 2y = 441 .... 2
Substitute 1 into 2;
1.5x + 2(x-14) = 441
1.5x+2x-28 = 441
3.5x = 441+28
3.5x = 469
x = 469/3.5
x = 134
Recall that y = x - 14
y = 134-14
y = 120
Hence 134 children and 120 adult plates were served
Answer:
CP = 8 cm
Step-by-step explanation:
Given two chords that intersect inside a circle, then then the product of the parts of one chord is equal to the product of the parts of the other chord, that is
DP × CP = AP × PB ← substitute values
6 × CP = 12 × 4
6CP = 48 ( divide both sides by 6 )
CP = 8
The angles must add to 180 degrees.
Since the angles are in the ratio 7:9:4, their measures are not 7, 9, and 4 since 7, 9, and 4 do not add to 180. If you multiply 7, 9, and 4 by the same number, the new numbers will be in the same ratio. Since we do not know what that number is, we can use x for it.
Multiply 7, 9, and 4 by x to get
7x, 9x, and 4x.
Now add them and set equal to 180.
Then solve for x.
7x + 9x + 4x = 180
20x = 180
x = 9
Now that we know x equals 9, substitute x with 9 and evaluate 7x, 9x, and 4x to find the actual angle measures.
7x = 7 * 9 = 63
9x = 9 * 9 = 81
4x = 4 * 9 = 36
The angles measure 63, 81, and 36 degrees.
