Answer:
1 ± √47
Step-by-step explanation:
Combine like terms in 2x^2 +3 x-7 =x^2 +5x +39:
2x^2 - x^2 = x^2 (first term);
3x - 5x = -2x (second term);
-7 - 39 = -46 (third term)
Then we have, all on the left side, x^2 - 2x - 46, which is a quadratic equation. Here the coefficients are a = 1, b = -2 and c = -46.
Then the discriminant, b^2 - 4ac, is:
(-2)^2 - 4(1)(-46) = 4 + 184.
The roots are:
-(-2) ±√188 2 ± √4√47
------------------- = -------------------
2 2
= 1 ± √47 (last of the answer choices)
=
x = ------------------
Answer: I wrote the answer in docs so here is the pic for the whole equation i explained it too! I hope this helped
Best way to tell is to convert them all to either decimals, fractions, or percentages. I usually convert to decimals. So, 75% is 0.75. 0.9 is already a decimal. And 4/5 is 0.8.
So 0.75, or 75%, is now clearly the smallest. In order from least to greatest, they go 75%, 4/5, and 0.9.
Answer:
Just match values.
At 1 hour you have 60 degrees
At 2 hour 65
At 3 70 degrees
At 4 75 degrees
As You can see the temperature varies by 5 degrees