Answer:
Cross multiplication is the method used to determine whether or not a proportion is true.
Explanation:
If you know one ratio in a proportion, you can use that information to find values in the other equivalent ratio.
Cross multiplication is the method used to determine whether or not a proportion is TRUE.
For example, if a bowl of fruit contains 10 oranges and 8 lemons, then the ratio of oranges to lemons is 10 is to 8 (that is, 10 : 8 ), which is equivalent to the ratio 5:4).
Isnt it 33 ////??? thats what i got.
Answer:
Step-by-step explanation:
Let the speed of Masha = s, speed of Dasha = d
- Distance = 20 km
- Time difference = 20 min = 1/3 hr
- Speed difference = 2 km/h
<u>As per above info we get following equations:</u>
- s = d + 2
- 20/s + 1/3 = 20/d
<u>Substitute s and solve for d:</u>
<u>Get rid of fraction by multiplying all terms by 3d(d + 2):</u>
- 60d + d(d + 2) = 60(d + 2)
- 60d + d² + 2d = 60d + 120
- d² + 2d = 120
- d² + 2d + 1 = 121
- (d + 1)² = 11²
- d + 1 = 11
- d = 10
<u>Find s:</u>
<u>The answer is</u>
- Masha's speed 12 km/h and Dasha's speed 10 km/h
Answer:
x² - 16xy + 64y²
Step-by-step explanation:
The difference of x and 8y is x - 8y
The square of the difference is (x - 8y)² = (x - 8y)(x - 8y)
Expand by multiplying each term in the second factor by each term in the first factor, that is
x(x - 8y) - 8y(x - 8y) ← distribute both parenthesis
= x² - 8xy - 8xy + 64y² ← collect like terms
= x² - 16xy + 64y²
