Ask question

Ask question

All categories

3 years ago

9

If x-5(x-7)=-7 then x equals what?

1 answer:

NeX [460]3 years ago

7 0

Expand

simplify x - 5x + 35 to -4x + 35

subtract 35 from both sides

simplify -7 - 35 to -42

divide both sides by -4

two negatives make a positive

simplify 42/4 to 21/2

Answer: x = 21/2.

You might be interested in

The sum of squares of three consecutive numbers is 77 find the numbers

ollegr [7]

Answer:

4,5,6 are the three consecutive numbers. 16, 25 and 36 are their squares.

Step-by-step explanation:

Let the three consecutive numbers be x, (x+1), (x+2)

Now, the squares of these three numbers are $x^{2} ,(x+1)^{2} ,(x+2)^{2}$

Sum = 77

∴by the problem ,

$x^{2} +(x+1)^{2}+(x+2)^{2} = 77\\x^{2} +(x^{2} +2x+1)+(x^{2}+4x +4) = 77\\x^{2} +x^{2} +2x+1+x^{2} +4x +4 = 77\\3x^{2} +6x+5 = 77\\3x^{2} +6x = 77-5\\3x^{2} + 6x = 72\\3x^{2} +6x-72= 0\\$

{Taking 3 common }

$x^{2} +2x- 24 = 0\\$

{By factorization}

$x^{2} +2x- 24 =0\\ x^{2} +6x-4x-24=0\\x(x+6)-4(x+6)=0\\(x+6)(x-4)=0\\$

Therfore,

$x= -6,4\\$

<em>X can't be negetive </em>

∴ $x =4\\x+1=5\\x+2=6$

The squares of the three consecutive numbers are 16, 25, 36

The three consecutive numbers whose sum is 77 are 4, 5, 6

3 0

4 years ago

How do I solve -4 times the square root of 1/10

schepotkina [342]

Answer: I think it is -0.4

Step-by-step explanation:

7 0

3 years ago

A bridge over a gorge is supported by an arch in the shape of a semi-ellipse. The length of the bridge is 400 ft. and the maximu

Hitman42 [59]

Answer:

The height of the arch 50ft from the center is 97ft

Step-by-step explanation:

A bridge over a gorge is supported by an arch in the shape of a semi-ellipse

The length of the bridge is 400 ft. and the maximum height is 100 ft

so, a=200ft

b=100ft

(a)

we can draw picture

(b)

now, we can use equation of ellipse formula

$\frac{x^2}{a^2}+ \frac{y^2}{b^2}=1$

now, we can plug

a=200

b=100

$\frac{x^2}{200^2}+ \frac{y^2}{100^2}=1$

we can plug x=50 and find y

$\frac{50^2}{200^2}+ \frac{y^2}{100^2}=1$

$y=25\sqrt{15}$

$y=97ft$

6 0

3 years ago

Let p= 7, q= V14, r = 3 Which of the following expressions is irrational?

user100 [1]

There is no other equations

8 0

3 years ago

QUICK HELP PLEASE THANKS<br> Find percent notation for 0.28.

rosijanka [135]

Answer:

28%

Step-by-step explanation:

Multiply both numerator and denominator by 100. We do this to find an equivalent fraction having 100 as the denominator. 0.28 × 100100.

= (0.28 × 100) × 1100 = 28100.

Write in percentage notation: 28%

5 0

3 years ago