1) plug in 1 for x to get the following:
1^2 + 2(1)
1^2 = 1
2 * 1 = 2
1 + 2 = 3
the answer is 3.
2) for estimating, your teacher may have another method but here's how i was taught:
determine whether to round up or down to a whole number:
7.9 rounds up to 8 and 0.67 rounds up to 1, and 8 * 1 is 8, so i would estimate the answer to be 8.
(i can't do the remaining two sorry!!)
Answer:
its +
Step-by-step explanation:
Let the number of corn acres be xx and the number of wheat acres be yy.
We are given that:
1- The total number of acres is 180, this means that:
xx + yy = 180 ..............> equation I
2- The number of corn acres is 3 times that of wheat. This means that:
xx = 3yy .........> equation II
Substitute with equation II in equation I to get the value of yy as follows:
xx + yy = 180
3yy + yy = 180
4yy = 180
yy = 45 acres
Now substitute with yy in equation II to get xx as follows:
xx = 3yy
xx = 3*45
xx = 135 acres
Based on the above calculations:
acres of corn = xx = 135 acres
acres of wheat = yy = 45 acres