Answer:
a) x = 12 y = 9
b) x = -2 y = -4
c) x = 6 y = -2
Step-by-step explanation:
a)
Equation 1: 6x - 7y = 9
Equation 2: 3x + 2y = 54
Multiply Equation 2 by 2:
⇒ 6x + 4y = 108
Subtract equations:
6x + 4y = 108
<u>- 6x - 7y = 9 </u>
11y = 99
Divide both sides by 11:
⇒ y = 9
Substitute found value of y into Equation 1 and solve for x:
⇒ 6x - 7(9) = 9
⇒ 6x - 63 = 9
⇒ 6x = 72
⇒ x = 12
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b)
Equation 1: 4x - 5y = 12
Equation 2: 2x - 3y = 8
Multiply Equation 2 by 2:
⇒ 4x - 6y = 16
Subtract equations:
4x - 6y = 16
<u>- 4x - 5y = 12 </u>
-y = 4
Divide both sides by -1:
⇒ y = -4
Substitute found value of y into Equation 1 and solve for x:
⇒ 4x - 5(-4) = 12
⇒ 4x + 20 = 12
⇒ 4x = -8
⇒ x = -2
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c)
Equation 1: 4x - 2y = 28
Equation 2: 3x + 3y = 12
Multiply Equation 1 by 3:
⇒ 12x - 6y = 84
Multiply Equation 2 by 4:
⇒ 12x + 12y = 48
Subtract equations:
12x - 6y = 84
<u>- 12x + 12y = 48 </u>
-18y = 36
Divide both sides by -18:
⇒ y = -2
Substitute found value of y into Equation 1 and solve for x:
⇒ 4x - 2(-2) = 28
⇒ 4x + 4 = 28
⇒ 4x = 24
⇒ x = 6
<span>2r2 + 3s3 − r2 + 4t2 − r2
</span>
= 19
Amount Earned (E) = 8.25*Hours (H)
Since he wants to buy a game system you can also write this as an inequality, if the amount of the game system has any relevance in the problem.
8.25*H >= 206.25
Answer:
number 21: 5 ten thousands, 7 hundreds, <em><u>7</u></em><em><u> </u></em>tens and 7 ones
Step-by-step explanation:
7 tens = 70
7 ones = 7
which equals 77, if the number is 50,777, you can see the last two digits in the tens and ones place are 7 and 7.
