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kupik [55]
3 years ago
7

Evaluate zx-xy-7 use x=-3, y=8, and z=-9*​

Mathematics
2 answers:
trapecia [35]3 years ago
8 0

Answer:

44

Step-by-step explanation:

1. substitute variables with their constants

(-9)(-3) - (-3)(8) - 7

2. multiply all like terms

(27) - (-24) - 7

3. Combine all like terms

27 + 24 - 7

51 - 7

= 44

lbvjy [14]3 years ago
3 0

Answer:

44

Step-by-step explanation:

Evaluate z x - x y - 7 where x = -3, y = 8 and z = -9:

z x - x y - 7 = -9 (-3) - -3×8 - 7

Hint: | Multiply -9 and -3 together.

-9 (-3) = 27:

27 - -3×8 - 7

Hint: | Multiply -1 and -3 together.

-(-3) = 3:

27 + 3×8 - 7

Hint: | Multiply 3 and 8 together.

3×8 = 24:

27 + 24 - 7

Hint: | Evaluate 27 + 24 using long addition.

| 1 |  

| 2 | 7

+ | 2 | 4

| 5 | 1:

51 - 7

Hint: | Subtract 7 from 51.

| 4 | 11

| 5 | 1

- | | 7

| 4 | 4:

Answer: 44

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Given m<br> n, find the value of x and y.<br> (37-18)<br> (8x+12)<br> m<br> (2X+18)<br> n
adelina 88 [10]

Answer:

Step-by-step explanation:

The two inside angles will sum to 180°.

The top to angles are equal.  

Think about this as what if both of the parallel lines were intersected by a perpendicuar line.  Every angle would be a right triangle 90°.  The inside angles will sum to 180° and the opposite angles are again equal.

 (2x + 18) + (8x + 12) = 180

          10x +   30   =   180

                   10x    =   150

                      x  =  15

-------------------------

             (3y - 18)  =  (8x + 12)       x = 15

            (3y - 18)  =  (8(15) + 12)

            (3y - 18)  =  (120 + 12)

            (3y - 18)  =  132

                   3y   =   132 + 18

                   3y   =  150

                     y   =  50

5 0
3 years ago
All I need is number six and seven which ever answer is the most reasonable I’ll mark you as brainliest
Dennis_Churaev [7]

Answer:

6. 141

7. 28

Step-by-step explanation:

Time to rewrite the expressions!

6. (8 + 45/9)² - 14(2)

First, we need to solve what's in the parentheses.

45/9 is 5. So 8 + 5 is 13. 13² - 14(2)

Now, the exponent. 13² = 169 (nice)

169 - 14(2) Multiply 14 and 2...

169 - 28 = 141

Now to rewrite 7.

12 + 36/2 - 3(1)²

Exponents first...

3² = 9 (the 1 isn't included 'cause 3 multiplied by 1 is still 3.)

12 + 36/2 - 12

Divide... 36/2 = 18

12 + 18 - 2

30 - 2

28

8 0
3 years ago
Do not use your calculator for Parts 1 through 4.
Hunter-Best [27]
You have to understand how piecewise functions first
I hope you do because I won't be explaining it here



1.
if it is continiuous at x=1 then the part of the function that approaches 1 from the left is the same value
so we have f(x)=3-x for x<1, so evaluate it for x=1,
we would get 3-1=2
so
if a=2 and b=3

f(x)=2x²+3x
for x=1, we get 2+3=5

it approaches 2 from the left but equals 5
2≠5
so it is not continuous because it doesn't approach the same value at x=1




2.
alright
so we established that it should approach 2 because we had the f(x)=3-x
so
f(1)=2=ax²+bx
2=a+b
the relationship is 2=a+b



3.
same as before, but use the other function, the one that is defined at x≥2
5x-10, 5(2)-10, 10-10, 0
it approaches 0
so
we must find one such that f(x)=0 for x=2 with the ax²+bx
0=a(2)²+b(2)
0=4a+2b
if we minus 2b both sides
-2b=4a
divide by 2
-b=2a
add b both sides
0=2a+b



4.
2=a+b
0=2a+b

2=a+b
minus b both sides
2-b=a
subsitute
0=2a+b
0=2(2-b)+b
0=4-2b+b
0=4-b
b=4

sub back
2-b=a
2-4=a
-2=a

a=-2
b=4


5.
graph f(x)=-2x²+4x from x=1 to x=2 and put a closed dot at (1,2) and an open dot at (2,0)
4 0
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The area of a rectangle is found by multiplying the base times the height. A rectangle with an area represented by 12x2 + 6x – 8
maria [59]
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7 0
3 years ago
Read 2 more answers
Knowing that sin 30º = 1/2 what is a?​
dimulka [17.4K]

Answer:

7

Step-by-step explanation:

7 0
3 years ago
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