Answer:
x = -8
y = 7
Step-by-step explanation:
5x + 7y = 9
2x - 3y = -37
1.) First, multiply each side to match either y-values or x-values. (In this example, we'll use match x-values)
10x + 14y = 18 (multiplied by 2)
10x - 15y = -185 (multiplied by 5)
2.) Then, subtract the entirety of one equation to isolate the y-value.
10x + 14y = 18
-10x + 15y = 185
3.) Add and subtract values and divide to find y.
29y = 203
y = 7
4.) Plug-in y to solve for x into one equation, or repeat steps 1-3.
15x + 21y = 27
14x - 21y = -259
29x = -232
x = -8
2.1+18.9
The answer is going to be 21 because 9+1=10, you then carry the 1 for 8 so it’s going to be 9+2 which equals to 11 now you carry the 1 to the 1 so it’ll be 2. Therefore it’s 21.0 or just cancel out the 0 and just leave it as 21.
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.
