Answer:
mean ≈ 25.45
Step-by-step explanation:
mean is calculated as
mean = 
We require the sum for both classes
class A
mean =
= 40 ( multiply both sides by 9 )
sum = 9 × 40 = 360
class B
mean =
= 20 ( multiply both sides by 24
sum = 24 × 20 = 480
Total sum for both classes = 360 + 480 = 840 , then mean for both classes is
mean =
≈ 25.45 ( to 2 dec. places )
Toothpaste and food coloring
Answer:

Step-by-step explanation:
we know that
Applying the law of cosines

we have

substitute



Answer:
y = 88
Step-by-step explanation:
Don't worry about the other stuff, just worry about what's in the triangle that has Y.
53°, 39°, and y°
the sum should be equal to 180 so add 53 adn 39 and subtract it from 180.
180 - (53 + 39) = y
180 - 92 = y
88 = y
Hope this helped! Pls Brainliest my answer! It would help amd mean a lot! ;)
Step-by-step explanation:
16.................................................
<h3>Given</h3>
- Equation ax² + bx + c = 0
- One of the roots is twice the other
<h3>To find</h3>
<h3>Solution</h3>
Let the roots be p and q
<u>The sum and product of the roots:</u>
<u>The sum of the roots, considering p = 2q,</u>
And
<u>The product of the roots, considering p = 2q:</u>
And
<u>Substitute q with -b/(3a)</u>
- 2(-b/(3a))² = c/a
- 2b²/(9a²) = c/a
- 2b² = 9a²(c/a)
- 2b² = 9ac
=================================================
17. .................................................
<h3>Given</h3>
Quadratic equation
- ax² = bx + c = 0, with equal roots
<h3>To find</h3>
<h3>Solution</h3>
<u>Equal roots means the discriminant is zero:</u>
- D = √b² - 4ac
- √b² - 4ac = 0
- b² - 4ac = 0
- b² = 4ac