(3x+2) (x-7)
FOIL
first 3x*x = 3x^2
outer 3x*-7 = -21x
inner = 2*x = 2x
last 2*-7 = -14
add them together = 3x^2 -21x+2x -14
combine like terms 3x^2 -19x -14
Answer:
x = (+ - ) 9
Step-by-step explanation:
x^2 = 81
u know how u can sometimes cancel something out by doing the opposite.
This is one of those times as well. the opposite of ^2 = square root.
so if we take the square root of both sides, this will cancel out the^2 on the left side.
sqrt (x^2) = sqrt(81)
x = (+-) 9.....thats a positive and a negative sign...because the sqrt of 81 is both 9 and -9.
Yes- though we may say "When will we ever use this?" ever so often in class, the reality is that we use mathematics in everyday life. From simple addition, to factoring, to finding the angles of various components to a building, math is always being used in real life.
Answer:
A. X=22
Step-by-step explanation:
x - 5 = 17
x =17 + 5
x = 22
Using the z-distribution, it is found that the 90% confidence interval for mean calories in a 30-gram serving of all chocolate chip cookies is (143, 149).
We are given the <em>standard deviation</em> for the population, which is why the <em>z-distribution </em>is used to solve this question.
The information given is:
- Sample mean of
.
- Population standard deviation of
.
- Sample size of
.
The confidence interval is:
The critical value, using a z-distribution calculator, for a <u>95% confidence interval</u> is z = 1.645, hence:


The 90% confidence interval for mean calories in a 30-gram serving of all chocolate chip cookies is (143, 149).
A similar problem is given at brainly.com/question/16807970