3.9 * 5.3 ≈ 4 * 5
≈20
Well after doing your multiplication, you can place your decimal point by knowing that from estimation the answer is around 20.
So you can place your decimal point after the first two digits from the left.
Answer:
-84
Step-by-step explanation:
Answer:
Length = 12 feet
Width = 30 feet
Step-by-step explanation:
Let l be the length of the garden and let w be the width:
We have system of equations
2w + l = 54
l = 2w + 6
We substitute 2w + 6 for l
2w + 2w + 6 = 54
4w + 6 = 54
4w = 54 - 6
4w = 48
w = 48/4
w = 12 feet
Width(w) = 12 feet
We find the Length
l = 2w + 6
l = 2(12) + 6
l = 24 + 6
I = 30 feet
First we'll do two basic steps. Step 1 is to subtract 18 from both sides. After that, divide both sides by 2 to get x^2 all by itself. Let's do those two steps now
2x^2+18 = 10
2x^2+18-18 = 10-18 <<--- step 1
2x^2 = -8
(2x^2)/2 = -8/2 <<--- step 2
x^2 = -4
At this point, it should be fairly clear there are no solutions. How can we tell? By remembering that x^2 is never negative as long as x is real.
Using the rule that negative times negative is a positive value, it is impossible to square a real numbered value and get a negative result.
For example
2^2 = 2*2 = 4
8^2 = 8*8 = 64
(-10)^2 = (-10)*(-10) = 100
(-14)^2 = (-14)*(-14) = 196
No matter what value we pick, the result is positive. The only exception is that 0^2 = 0 is neither positive nor negative.
So x^2 = -4 has no real solutions. Taking the square root of both sides leads to
x^2 = -4
sqrt(x^2) = sqrt(-4)
|x| = sqrt(4)*sqrt(-1)
|x| = 2*i
x = 2i or x = -2i
which are complex non-real values
