Answer:
A = choosing a red marble
B = choosing a green marble
Probability of A happening = P(A) = 5/(3+5+4) = 5/12
Probability of B happening = P(B) = 4/(3+5+4) = 4/12
Probability of either happening = P(A) + P(B) = 5/12 + 4/12 = 7/12
The key word in their question is red OR green and that is why we add the two probabilities. If they ask the probability of them both happening (if they said red AND green), you would multiply P(A)*P(B).
Answer:
y = 50
Step-by-step explanation:
All triangle angles add up to 180 degrees.
To set this equation up, you need to add everything given in the triangle and set it equal to 180:
y + y + 80 = 180
<em><u>Add like terms:</u></em>
2y + 80 = 180
<u><em>Subtract 80 from both sides:</em></u>
2y + 80 = 180
- 80 - 80
___________
2y = 100
<u><em>Divide both sides by 2:</em></u>
y = 50
<u><em>If you're unsure, you can plug in the 50 for y:</em></u>
y + y + 80 = 180
50 + 50 + 80 = 180
100 + 80 = 180
180 = 180
Answer:
A) 
Step-by-step explanation:
Area of a trapezoid is 
Answer:
-25
Step-by-step explanation:
(1) y = -2x²
(2) y = 2x² + k Subtract (1) from (2)
0 = 4x² + k Subtract 4x² from each side
k = -4x²
The parabolas are <em>symmetrical about the y-axis.</em>
Segment AB = 5, so x = +2.5 and x = +2.5.
k = -4(±2.5)² = -4 × 6.25 = -25
