The idea of grouping is to get the terms in groups that allow you to factor out from each group something that becomes a factor in itself, leaving two factors behind that are alike. Like this: rearrange those terms so they are in this order:
(-70y^2 - 63xy) + (90x^3 + 100yx^2). Now out of the first set we are going to factor out a -7y, and out of the second set we are going to factor out a 10x^2. When we do this, this is what we get: -7y(10y + 9x) + 10x^2(9x + 10y). As you can see, what's inside both sets of parenthesis is the same, just in a different order. We can factor that out now, leaving (9x + 10y)(10x^2 - 7y). And that is factored by grouping.
Answer: 36 years
Step-by-step explanation:
You can use the Rule of 72 to calculate how long it might take the house to double in value.
The Rule of 72 works by dividing 72 by the interest rate as a whole number and the result will be a rough estimate of the time in years it will take for the investment to double in size:
= 72 / 2
= 36 years
Answer:
Joseph caught 7 tadpoles
Step-by-step explanation:
Let the number of tadpoles caught by Joseph be x
The number of tadpoles Wendy caught will be ;
9(x + 3)
After Joseph was upset, he released half of Wendy’s tadpole and then six times as many as Joseph caught swam away leaving Wendy with only three tadpoles left;
Hence, mathematically;
9(x + 3)/2 - 6x = 3
Multiply through be 2
9(x + 3) - 12x = 6
9x + 27 -12x = 6
9x -12x = 6-27
3x = 21
x = 21/3
x = 7
I think the answer is 2 13/20
Or, in decimals: 1.3
Answer:
94 tons I got a 100 in the test
