x² - 80 = 0
Add 80
to each side: x² = 80
Square root
each side: x = √80
Look it up: x = + 8.944... (rounded)
and
x = - 8.944... (rounded).
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Here's a cleaner solution:
x² - 80 = 0
Add 80
to each side: x² = 80
Square root
each side: x = √80
But 80 = 16 · 5
So √80 = √16 · √5
√16 = 4, so x = 4 √5
Answer: B: 70, 80, 30
Step-by-step explanation:
An acute triangle has all 3 angles at less than 90 degrees, therefore the answer is B because its the only one that has all three at <90
Based on the given figure above, here is how you get the area.
Firstly, you get the area of the part with the measurement of 4m and 4m. This has the same measurement of the sides so it is easier to find the area. The formula for the area of the square is s x s. So 4m x 4m is 16m^2. Next, get the area of the rectangle part. Getting the area of the rectangle is l x w. So 9m x 10m would be 90m^2. Now add both values and you get 106m^2. So the answer is option B.
