Answer:
80/3
Step-by-step explanation:
same distance is covered at different speed , avg speed= 2ab/a+b
= 2*20*40/60
= 80/3
Answer:
Step-by-step explanation:
3rd one
Answer:
the teacher should be sad. the correct answer is 68 inches is NOT greater than 70 inches, therefore a triangle can't be created
Step-by-step explanation:
in a triangle, 2 sides added together have to be greater than the third side or else the triangle can't be created. therefore, since 31+37=68 inches, and 68<70, the triangle can't be created.
Answer:
Step-by-step explanation:
Lisha is making headbands using ribbon.
each one requires 15.5 inches of ribbon
For 12 headbands Lisha need to buy ribbon = 15.5 × 12
= 186 inches
Therefore, Lisha will need to buy 186 inches ribbon.
160 inches ribbon is not sufficient to make 12 headbands. She will need to buy 186 inches or more.
This is a stupid question. The teacher who asked this needs to go back to school.
A = x⁴ - 9y²
That's going to be a number. As long as it's positive we can choose any length for our rectangle L and we can compute the width by W=A/L. So the correct answer is the dimensions are L by (x⁴ - 9y²)/L.
They don't want the correct answer. They want you to factor this expression. We'll do it, but don't believe for a second this factoring somehow constrains the possible dimensions of some rectangle.
We use the difference of two squares, a²-b² = (a+b)(a-b)
A = x⁴ - 9y² = (x²)² - (3y)² = (x²+3y)(x²-3y)
Answer: x²+3y by x²-3y