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
-------------
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:
See below.
Step-by-step explanation:
the one on the left area is 104
the one on the right area is 19.5
Graph the line using the slope and y-intercept, or two points.
Slope:
−
1
-
1
Y-Intercept:
−
2
-
2
x
y
0
−
2
1
−
3
Please mark BRAINLIEST ❤️
The surface area of a cylinder with circular bases of radius <em>r</em> and height <em>h</em> is equal to the sum of the areas of the two circular faces and the area of the rectangular lateral surface:
<em>A</em> = 2π<em>r</em>² + 2π<em>rh</em>
If you know the height <em>h</em>, then you can solve the quadratic equation for <em>r</em>.
H 45%
you would add up the number of shaded squares and divide that by the total number of squares