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.
