Answer:
A: x = 20
C: x = -9
Step-by-step explanation:
You can solve the inequality and compare that with the offered choices, or you can try the choices in the inequality to see if it is true. Either approach works, and they take about the same effort.
<u>Solving it</u>:
Unfold it ...
-17 ≤ x -7.5 ≤ 17
Add 7.5 ...
-9.5 ≤ x ≤ 24.5
The numbers 20 and -9 are in this range: answer choices A and C.
_____
<u>Trying the choices</u>:
A: |20 -7.5| = 12.5 ≤ 17 . . . . this works
B: |-10 -7.5| = 17.5 . . . doesn't work
C: |-9 -7.5| = 16.5 ≤ 17 . . . . .this works
D: |27-7.5| = 19.5 . . . doesn't work
The choices that work are answer choices A and C.
Answer:
(3x+4)(5x+7)
Step-by-step explanation:
15x^2
+41x+28
Factor the expression by grouping. First, the expression needs to be rewritten as 15x^2
+ax+bx+28. To find a and b, set up a system to be solved.
a+b=41
ab=15×28=420
Since ab is positive, a and b have the same sign. Since a+b is positive, a and b are both positive. List all such integer pairs that give product 420.
1,420
2,210
3,140
4,105
5,84
6,70
7,60
10,42
12,35
14,30
15,28
20,21
Calculate the sum for each pair.
1+420=421
2+210=212
3+140=143
4+105=109
5+84=89
6+70=76
7+60=67
10+42=52
12+35=47
14+30=44
15+28=43
20+21=41
The solution is the pair that gives sum 41.
a=20
b=21
Rewrite 15x^2
+41x+28 as (15x^2
+20x)+(21x+28).
(15x^2
+20x)+(21x+28)
Factor out 5x in the first and 7 in the second group.
5x(3x+4)+7(3x+4)
Factor out common term 3x+4 by using distributive property.
(3x+4)(5x+7)
Answer: 800 feet²
Step-by-step explanation:
Lets remove the brackets from the function's expression
A(x) = -2x²+80x
So we got the quadratic function and we have to find the x that corresponds to function's maximum. Let it be X max
As we know Xmax= (X1+X2)/2 , where X1 and X2 are the roots of the function A(x)
Lets find X1 and X2
x(80-2x)=0
x1=0 80-2*X2=0
x2=40
So Xmax= (0+40)/2=20
So Amax= A(20)= 20*(80-2*20)=20*40=800 feet²
(5,-2)(-3,4)
slope = (4 - (-2) / (-3 - 5) = 6/-8 = - 3/4
y = mx + b
slope(m) = -3/4
use either of ur points...(5,-2)...x = 5 and y = -2
now we sub and find b, the y int
-2 = -3/4(5) + b
-2 = -15/4 + b
-2 + 15/4 = b
-8/4 + 15/4 = b
7/4 = b
so ur equation is : y = -3/4x + 7/4 <==
Answer:
C
Step-by-step explanation:
umm ..it's right i think
