x = number of 1-cent stamps
y = number of 8-cent stamps
z = number of 12-cent stamps
We have 31 stamps all together, so x+y+z = 31.
"I have 4 more 1-cent stamps than 8-cent stamps" means we have the equation x = y+8. Whatever y is, add 8 to it to get x. Solve for y to get y = x-8.
You also have "twice as many one cent stamps as 12 cent stamps", so x = 2z. Solving for z gets you z = 0.5x
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x+y+z = 31
x+x-8+z = 31 ... y replaced with x-8
x+x-8+0.5x = 31 ... plug in z = 0.5x
2.5x-8 = 31
2.5x = 31+8
2.5x = 39
x = 39/2.5
x = 15.6
Your teacher made a typo somewhere because we should get a positive whole number result for x (since x is a count of how many 1-cent stamps we have).
We have 2.48>2.4 1>2.463. If we insert a '7' between that 4 and 1, we get:
2.48 > 2.471 >2.463, and this is true.
Answer:
x = HJ/5 + 3/5
HJ = 5x - 3 = 5 (11) - 3 = 55 - 3 = 52
JK = 8x - 9 = 8(11) - 9 = 88 - 9 = 79
Answer:
D A = (1/2) (y₂ - y₁)(x₃ - x₁)
Step-by-step explanation:
b = (y₂ - y₁)
h = (x₃ - x₁)
A = (1/2)bh
A = (1/2) (y₂ - y₁)(x₃ - x₁)