If you have a problem like:
4x+2y=20
2x+2y=16
You would subtract
4x-2y=20
-2x+2y=16
You would get the new problum
2x=4
You now want to divide the 2 on both sides to solve for x
x=2
Now that you've solved for X you want to solve for y. So use substitution to solve for y. You would want to substatute the x for the 2 in either of the problums. I'll use the first one.
4(2)+2y=20
You first want to multiply te 4(2) you would get a new problum.
8+2y=20
Now you want to subtract the 8 on both sides.
2y=12
The last step to solve for y is to divide the 2 on both sides.
Y=6
So your answers would be
x=2
y=6
A ratio is a comparison of two values. In this case, there are 6 boys to every 15 girls. So, this means the ratio is 6:15.
Hopefully, this helps!
X + 3x + 4x = 56
8x = 56
x = 7
The shortest piece is 7 inches
The middle piece is 7*3 = 21 inches.
The longest piece is 4*7 = 28 inches
Check
7 + 21 + 28 = 56 It does check and the lengths are correct.
Answer:
a) y-intercept = 17; initial design strength percentage
b) slope = 2.8; increase in that percentage each day
c) 29.6 days to 100% design strength
Step-by-step explanation:
a, b) The equation is in the form called "slope-intercept form."
y = mx + b
where the slope is m, and the y-intercept is b.
Your equation has a slope of 2.8 and a y-intercept of 17.
The y-intercept is the percentage of design strength reached 0 days after the concrete is poured. The strength of the concrete when poured is 17% of its design strength.
The slope is the percentage of design strength added each day after the concrete is poured. The concrete increases its strength by 2.8% of its design strength each day after it is poured.
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c) To find when 100% of design strength is reached, we need to solve for x:
100 = 2.8x +17
83 = 2.8x
83/2.8 = x ≈ 29.6
The concrete will reach 100 percent of its design strength in about 30 days.
