Answer:
a = 3, b = -1
Step-by-step explanation:
a = 5b + 8
a = -10b - 7
5b + 8 = -10b - 7
Add 10b from both sides;
15b + 8 = -7
Subtract 8 from both sides;
15b = -15
Divide both sides by 15;
b = -1
Lets substitute b;
a = 5b + 8
a = 5(-1) + 8
a = -5 + 8
a = 3
Answer:
Step-by-step explanation:
2/3 ÷ 1/3
=2/3 × 3/1 (recipracol)
=6/3
=2
2 times 2.5 times 1.5 times 10 equals to 75 square meters.
Answer:
31 children and 290 adults
Step-by-step explanation:
Let a = number of adults and c = number of children.
a + c = 321
2a + 1.75c = 634.25
Multiply both sides of the the first equation by -2 and add it to the second equation.
-2a - 2c = -642
(+) 2a + 1.75c = 634.25
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-0.25c = -7.75
Divide both sides by -0.25
c = 31
Use the first equation to find a.
a + c = 321
Substitute 31 for c.
a + 31 = 321
Subtract 31 from both sides.
a = 290
Answer: 31 children and 290 adults
