Answer:
This means that Alex answered 14 questions correctly
Step-by-step explanation:
<u>Step 1: Find an equation</u>
20 * 0.7 = x
<u>Step 2: Multiply</u>
20 * 0.7 = x
14 = x
Answer: This means that Alex answered 14 questions correctly
The dimension of one side of the stamp was 2 centimeters
Step-by-step explanation:
The formula of the area of any square is A = l², where l is the
length of the side of the square
lance bought a square postage stamp to a mail a card to his cousin
∵ The stamp has 4 square centimeters
∴ The area of the stamp = 4 cm²
∵ The stamp shaped a square
∵ The formula of the area of the square is A = l²
- Equate the formula of the area of the square by the area of the stamp
∴ l² = 4
- Take √ for both sides to find l
∴ 
∴ l = 2 cm
The dimension of one side of the stamp was 2 centimeters
Learn more:
You can learn more about the area of the shapes in brainly.com/question/10677255
#LearnwithBrainly
Step-by-step explanation:
let's look at the full numbers under the square roots when bringing the external factors back in :
sqrt(9×9×2) - sqrt(3×3×7) + sqrt(8) - sqrt(28)
and let's present these numbers as the product of their basic prime factors
sqrt(3×3×3×3×2) - sqrt(3×3×7) + sqrt(2×2×2) - sqrt(2×2×7)
now we see that we have 2 pairs of square roots : 1 pair ends with a factor of 2, and one pair with a factor of 7.
let's combine these
sqrt (3×3×3×3×2) + sqrt(2×2×2) - sqrt(3×3×7) - sqrt (2×2×7)
and now we move the factors of 2 and 7 back out in front (of course, we need to apply the square root on these factors) :
9×sqrt(2) + 2×sqrt(2) - 3×sqrt(7) - 2×sqrt(7) =
= (9+2)×sqrt(2) - (3+2)×sqrt(7) = 11×sqrt(2) - 5×sqrt(7)
and that is the first answer option.