Answer: 9 minutes
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Step-by-step explanation:
x = number of minutes
y = temperature
The equation is
y = 23x+68
The slope 23 tells us how fast the oven is heating up. The 68 is the y intercept, and it's the starting temperature (when x = 0).
We want to find the value of x when y = 275
y = 23x+68
275 = 23x+68
275-68 = 23x
207 = 23x
23x = 207
x = 207/23
x = 9
It takes 9 minutes for the oven to reach a temperature of 275°F
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Check:
y = 23x+68
y = 23*9+68
y = 207+68
y = 275
The answer is confirmed.