Answer: She added 7x and 3y
Step-by-step explanation: The final answer should be 7x + 3y, not 10xy.
Surface area of a cube = 6l²
Now given length = l = 8 mm
= 6*8² = 6*64 = 384 mm².
Thank you !!
Answer:
tons of high steel and 
tons of low steel
Step-by-step explanation:
Let x be the number of tons of high grade steel and y be the number of tons ow low grade steel needed.
In x tons of high grade steel there are
tons of iron
tons of magnese
In y tons of low grade steel there are
tons of iron
tons of magnese
NASA orders 500 tons of steel, so
and specifies that it must be in the proportion 80% iron and 20% magnese, so
From the first equation,
Substitute it into the second equation:
The correct answer is -1.
In order to solve this, we need to split into the positive and negative version of the answers. Let's start with the positive version.
2 - x < 4
-x < 2
x > -2 ----> NOTE: When we divide by -1, we have to change the direction of the sign.
Now we'll do the negative version.
2 - x > -4
-x > -6
x < 6
So we know the number must be greater than -2, but less than 6. The only number on this list that fits that is -1.
