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3 years ago

Find x if f(x) = 2x + 7 and f(x) = -1.

Mathematics

2 answers:

Yuri [45]3 years ago

8 0

Ok so i do not know if you mean to solve it?But the answer would be x=-4 if you solve the problem

Sloan [31]3 years ago

6 0

The answer we -9 because 2x-1 is -2 and -2+7= -9

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Number 25 please help

8_murik_8 [283]

I believe this is how you solve it

7 0

3 years ago

Matthew invested $3,000 into two accounts. One account paid 3% interest and the other paid 8% interest. He earned 4% interest on

boyakko [2]

Answer:

Mathew invested $600 and $2400 in each account.

Solution:

From question, the total amount invested by Mathew is $3000. Let p = $3000.

Mathew has invested the total amount $3000 in two accounts. Let us consider the amount invested in first account as ‘P’

So, the amount invested in second account = 3000 – P

Step 1:

Given that Mathew has paid 3% interest in first account .Let us calculate the simple interest $(I_1)$ earned in first account for one year,

$\text {simple interest}=\frac{\text {pnr}}{100}$

Where

p = amount invested in first account

n = number of years

r = rate of interest

hence, by using above equation we get $(I_1)$ as,

$I_{1}=\frac{P \times 1 \times 3}{100}$ ----- eqn 1

Step 2:

Mathew has paid 8% interest in second account. Let us calculate the simple interest $(I_2)$ earned in second account,

$I_{2} = \frac{(3000-P) \times 1 \times 8}{100} \text { ------ eqn } 2$

Step 3:

Mathew has earned 4% interest on total investment of $3000. Let us calculate the total simple interest (I)

$I = \frac{3000 \times 1 \times 4}{100} ----- eqn 3$

Step 4:

Total simple interest = simple interest on first account + simple interest on second account.

Hence we get,

$I = I_1+ I_2 ---- eqn 4$

By substituting eqn 1 , 2, 3 in eqn 4

$\frac{3000 \times 1 \times 4}{100} = \frac{P \times 1 \times 3}{100} + \frac{(3000-P) \times 1 \times 8}{100}$

$\frac{12000}{100} = \frac{3 P}{100} + \frac{(24000-8 P)}{100}$

12000=3P + 24000 - 8P

5P = 12000

P = 2400

Thus, the value of the variable ‘P’ is 2400

Hence, the amount invested in first account = p = 2400

The amount invested in second account = 3000 – p = 3000 – 2400 = 600

Hence, Mathew invested $600 and $2400 in each account.

3 0

3 years ago

Read 2 more answers

X=4y-7 2x+9y=-31 What be the answer

dybincka [34]

Answer:

x=-11

y=-1

Step-by-step explanation:

x=4y-7

2x+9y=-31

2(4y-7)+9y=-31

8y-14+9y=-31

17=-31+14

17y=-17

y=-1

x=4(-1)-7

x=-11

7 0

3 years ago

Read 2 more answers

A diameter of the sphere is MT CT CD

iren2701 [21]

Answer:

Step-by-step explanation:

The diameter is the longest possible line through the sphere and passes through the center.

3 0

3 years ago

Select the correct answer from each drop-down menu.

finlep [7]

Answer:

Coordinates of point B are (10,-4)

Coordinates of point D are (3.6,-0.4)

Step-by-step explanation:

1) Point C(3.6, -0.4) divides in the ratio 3 : 2. If the coordinates of A are (-6, 5), the coordinates of point B are ____

Let the coordinates of B be $(x_2,y_2)$

Coordinates of A = $(x_1,y_1)=(-6,5)$

Coordinates of C=(x,y)=(3.6,-0.4)

We will use section formula over here

$x=\frac{mx_2+nx_1}{m+n} , y = \frac{my_2+ny_1}{m+n}$

m:n=3:2

$3.6=\frac{3x_2+2(-6)}{3+2} , -0.4=\frac{3y_2+2(5)}{3+2}3.6 \times 5 = 3x_2-12, -0.4 \times 5 = 3y_2+10\\18+12=3x_2 , -2=3y_2+10\\30=3x_2 , -12=3y_2\\10=x_2, -4=y_2\\$

Coordinates of B = (10,-4)

2)If point D divides in the ratio 4 : 5, the coordinates of point D are ____

(fraction)

Let the coordinates of D be $(x,y)$

Coordinates of A = $(x_1,y_1)=(-6,5)$

Coordinates of B= $(x_2,y_2)=(10,-4)$

We will use section formula over here

$x=\frac{mx_2+nx_1}{m+n} , y = \frac{my_2+ny_1}{m+n}$

m:n=3:2

$x=\frac{3(10)+2(-6)}{3+2} , y=\frac{3(-4)+2(5)}{3+2}\\x=3.6,y=-0.4$

Coordinates of point B are (10,-4)

Coordinates of point D are (3.6,-0.4)

4 0

3 years ago