A shape that has four corners and four sides like a square, rectangle, or dimond
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).
Answer:
5.4 > x > 2.8
Step-by-step explanation:
Sum of two sides is always greater than the third side
Case1 :
4.1 + 1.3 > x
5.4 > x
Case2:
4.1 + x > 1.3 or 1.3 + x > 4.1
x > 1.3 - 4.1 or x > 4.1 - 1.3
x > - 2.8 or x > 2.8
Note that it is obvious x is not -ve so neglect -2.8. x > 2.8
Hence,
5.4 > x > 2.8
1sec = 3.6 x 10^5gallons
1 hr = 3600 x 3.6 x 10^5gallons
1hr = 1.296 x 10^9 gallons
