All categories

3 years ago

Solve for x.

Mathematics

2 answers:

grigory [225]3 years ago

7 0

Answer:

x=9

Step-by-step explanation:

x+3=12

x+3-3=12-3

x=9

zubka84 [21]3 years ago

3 0

The correct answer is 9

You might be interested in

PLEASE HELP ME ASAP!

TEA [102]

Answer:

x=5, y=2

Step-by-step explanation:

You simply write down what you see:

3x - 4y + 4x - 5y = 17

2x - 3y + 3x - 5y = 9

Then you simplify by grouping the x and the y terms:

7x - 9y = 17

5x - 8y = 9

Now you want to get equal amounts of x or y. Let's go for x. If we multiply the top eq with 5 and the bottom one with -7, we get:

35x - 45y = 85

-35x + 56y = -63

-------------------------+ now we can add them:

11y = 22 divide by -11

y = 2

So 7x - 18 = 17, x =5

Finally, it makes sense to double check by filling in these answers in the original equations, just to see if no mistakes were made:

3*5 - 4*2 = 7

4*5 - 5*2 = 10

7+10 = 17: ok!

2*5 - 3*2 = 4

3*5 - 5*2 = 5

4+5 = 9: ok!

4 0

3 years ago

Graph f(x) =-2x^+16x-30 by factoring to find the solutions, then find the coordinates of the vertex, and the axis of symmetry. I

fredd [130]

Answer:

Observe attached image

Function zeros:

(3, 0), (5, 0)

Vertex:

(4, 2)

Axis of symmetry:

 $x =4$ 

Step-by-step explanation:

First factorize the function

$f (x) = -2x ^ 2 + 16x-30$

Take -2 as a common factor.

$-2(x ^ 2 -8x +15)$

Now factor the expression $x ^ 2 -8x +15$

You must find two numbers that when you add them, obtain the result -8 and multiplying those numbers results in 15.

These numbers are -5 and -3

Then we can factor the expression in the following way:

$f (x) = -2(x-5)(x-3)$

The quadratic function cuts the x-axis at x = 3 and at x = 5.

Now we find the coordinates of the vertex.

For a function of the form $ax ^ 2 + bx + c$ the x coordinate of its vertex is:

$x = \frac{-b}{2a}$

In the function $f (x) = -2x ^ 2 + 16x-30$

$a = -2\\b = 16\\c = 30$

Then the vertice is:

$x = \frac{-16}{2(-2)}\\\\x = 4$

The y coordinate of the symmetry axis is

$y = f (4) = -2 (4) ^ 2 +16 (4) -30\\\\y = 2$

The axis of symmetry is a vertical line that cuts the parabola in two equal halves. This axis of symmetry always passes through the vertex.

Then the axis of symmetry is the line

$x = 4$

The solutions and the vertice written as ordered pairs are:

Function zeros:

(3, 0), (5, 0)

Vertex:

(4, 2)

6 0

3 years ago

Someone answerrrrrr plssss ASAP!!!!!!’

ikadub [295]

Answer:

9. It seems he was inactive/taking a break, as the line is completely straight.

I'm not sure about the others, but I hope that helps!

Step-by-step explanation:

4 0

3 years ago

Total of 49 1/4 + 3 3/8

Ede4ka [16]

49*4=196+1=197/4
8*3=24+3=27/8 

then make the denominator the same
multiply 197*2 and 4*2 = 394/8 
then 394/8 +27/8 =421/8 
u can either leave it here or in decimal form which would be 52.625 or in mixed numbers-52 5/8

3 0

3 years ago

Write a expression that can be used to multiply 6x198

nydimaria [60]

In this problem, we are asked to give an expression that can be used to mentally multiply 6 and 198. In order not to go through the rigorous multiplication, we can estimate 198 to 200, that is 6 *200 equal to 1200. Since there is a 2*6 excess or 12 then we subtract: 1200 -12 equal to 1188.

8 0

3 years ago