d) You have a <u>difference of squares</u>:
49y² - 9 = (7y)² - 3²
Recall the identity,
a² - b² = (a - b) (a + b)
So,
49y² - 9 = (7y - 3) (7y + 3)
e) Pull out the common factor 3 from each term:
3x² - 3x - 90 = 3 (x² - x - 30)
Now use the <u>sum-product method</u>. Notice that we can write 30 = 5 • 6, and 5 - 6 = 1, so
3x² - 3x - 90 = 3 (x + 5) (x - 6)
f) Same as in (e), use the <u>sum-product method</u>. Notice that 42 = 7 • 6, and -7 - 6 = -13, so
x² - 13x + 42 = (x - 7) (x - 6)
Answer:
Please read the answers below.
Step-by-step explanation:
Let's calculate the four means between 100 and 135, this way:
1. Arithmetic mean:
(100 + 135)/2 = 117.5
2. Weighted mean:
We will assign equal weight to both numbers : 5
(100 * 5 + 135 * 5)/10 = (500 + 675)/10 = 1,175/10 = 117.5
3. Geometric mean:
√100 * 135 = √13,500 = 116.2 (Rounding to the next tenth)
4. Harmonic mean:
2/(1/100 + 1/135) = 2/(0.01 + 0.0074) = 114.9 (Rounding to the next tenth)
Answer:
25
Step-by-step explanation:
so you have your two equations 3x+7=5x-23 and solve for x which is your "number" leaving the answer to be <u>x=15</u>
8 - 8x is already in its simplest form.
Without knowing the value of x, you cannot find what is equivalent to 8 - 8x, but you can it if is an equation, such as 8 - 8x = 88 (x would be -10).
However, you can still rewrite it as -8x + 8, which is equivalent to 8 - 8x.