Ahhhh i need help again.

Mathematics

1 answer:

qwelly [4]3 years ago

3 0

Answer:

Step-by-step explanation:

A. these simply to 21 + 7x and 21 + 3x

this one is incorrect because the 7x and 3x are different

B. these simplify to 10 + x and 10 + x

this is the correct one since they are exactly the same

C. these simplify to 21x and 7x + 21

these two are not the same because one expression has only a number with a variable but the other one has a number with a variable <em>and </em>another number

D. these simplify to $\frac{7}{3-x}$ and $\frac{7}{x-3}$

in subtraction, the order of the 3 and the x matters, so the equations are not the same
example: 6 - 4 = 2 but 4 - 6 = -2

You might be interested in

Evaluate the following expression:<br> -X- 6x + 10 when x = 5

BigorU [14]

Answer:

-25

Step-by-step explanation:

Evaluate -x - 6 x + 10 where x = 5:

-x - 6 x + 10 = -5 - 6×5 + 10

-6×5 = -30:

-5 + -30 + 10

-5 - 30 + 10 = 10 - (5 + 30):

10 - (5 + 30)

5 + 30 = 35:

10 - 35

10 - 35 = -(35 - 10):

-(35 - 10)

| 3 | 5

- | 1 | 0

| 2 | 5:

Answer: -25

8 0

3 years ago

PLEASE HELP I NEED THIS ASAP<br> Find the vertex of y=x^2-7x+4

Goshia [24]

Answer:

$\mathrm{Minimum}\space\left(\frac{7}{2},\:-\frac{33}{4}\right)$

Step-by-step explanation:

$y=x^2-7x+4\\\mathrm{The\:vertex\:of\:an\:up-down\:facing\:parabola\:of\:the\:form}\:y=ax^2+bx+c\:\mathrm{is}\:x_v=-\frac{b}{2a}\\\mathrm{The\:parabola\:params\:are:}\\a=1,\:b=-7,\:c=4\\x_v=-\frac{b}{2a}\\x_v=-\frac{\left(-7\right)}{2\cdot \:1}\\\mathrm{Simplify}\\x_v=\frac{7}{2}\\\mathrm{Plug\:in}\:\:x_v=\frac{7}{2}\:\mathrm{to\:find\:the}\:y_v\:\mathrm{value}\\y_v=\left(\frac{7}{2}\right)^2-7\cdot \frac{7}{2}+4\\$

$\mathrm{Simplify\:}\left(\frac{7}{2}\right)^2-7\cdot \frac{7}{2}+4:\quad -\frac{33}{4}\\y_v=-\frac{33}{4}\\Therefore\:the\:parabola\:vertex\:is\\\left(\frac{7}{2},\:-\frac{33}{4}\right)\\\mathrm{If}\:a0,\:\mathrm{then\:the\:vertex\:is\:a\:minimum\:value}\\a=1\\\mathrm{Minimum}\space\left(\frac{7}{2},\:-\frac{33}{4}\right)$