All categories

2 years ago

Solve the system of equations. 4х – 3y = 12 3х + 6у = 42

Mathematics

2 answers:

Firdavs [7]2 years ago

8 0

Answer: B. (6,4)

Find x for the 2nd equation

3x + 6y = 42

3x = 42-6y

x= (42-6y) / 3

Place the value of x in the first equation and find for y then.

4x - 3y= 12

4{(42-6y)/3} - 3y = 12

So the answer for y is 4

Now, you know the value of y is 4.

4x - 3*4 = 12

4x - 12 = 12

x= 12+12 /4

x= 6

So x is 6 and y is 4. So the answer is B.

Shkiper50 [21]2 years ago

6 0

The answer would be B) 6, 4

mark me brianliest if i was correct!

You might be interested in

I need help finding the equation of the line. Could someone please help me? Thanks.

anyanavicka [17]

The slope is 2/3, and the y-intercept is 4. In slope intercept form, the equation is y=2/3x+4

3 0

3 years ago

12. Find the surface area of each figure to the nearest tenth.

Zolol [24]

Answer:

12a. 471.2 cm²

12b. 60 m²

Step-by-step explanation:

Part A.

The surface area of each figure is the sum of the end area and the lateral area.

cylinder

S = (2)(πr²) +2πrh = 2πr(r +h)

S = 2π(5 cm)(5 cm +10 cm) =150π cm² ≈ 471.2 cm²

triangular prism

S = (2)(1/2)bh + PL . . . . b=triangle base; h=triangle height; P=triangle perimeter; L=length of prism

S = (4 m)(1.5 m) + ((4 + 2·2.5) m)(6 m) = (6 + 54) m² = 60 m²

_____

Part B.

Surface area is useful in the real world wherever products are made from sheets of material or wherever coverings are applied.

Carpeting or other flooring, paint, wallpaper are all priced in terms of the area they cover, for example.

The amount of material used to make containers in the shapes shown will depend on the area of these containers (and any material required for seams).

6 0

2 years ago

(i) 3 (a + 5b) + a (a + 4) (ii) y (10 - y) + 3 (y - 2) (iii) 2 (8a - 5b) + 3 (5a - 12) (iv) 3 (y - 3) + ( 8 - 6y + x) (v) a (a -

AveGali [126]

Answer:

$3 (a + 5b) + a (a + 4) = a^2 + 7a + 15b$

$y (10 - y) + 3 (y - 2) = - y^2+13y - 6$

$2 (8a - 5b) + 3 (5a - 12) = 31a -10b - 36$

$3 (y - 3) + ( 8 - 6y + x) = -3y + x-1$

$a (a - 2b) + b (b + 2a - c) =a^2 + b^2 - bc$

$5 (x - y + z) + (4x + 3y) =9x - 2y +5z$

Step-by-step explanation:

Solving (i):

$3 (a + 5b) + a (a + 4)$

Open brackets

$3 (a + 5b) + a (a + 4) = 3a + 15b + a^2 + 4a$

Collect like terms

$3 (a + 5b) + a (a + 4) = a^2 + 4a+3a + 15b$

$3 (a + 5b) + a (a + 4) = a^2 + 7a + 15b$

Solving (ii)

$y (10 - y) + 3 (y - 2)$

Open bracket

$y (10 - y) + 3 (y - 2) = 10y - y^2 + 3y - 6$

Collect like terms

$y (10 - y) + 3 (y - 2) = - y^2+10y + 3y - 6$

$y (10 - y) + 3 (y - 2) = - y^2+13y - 6$

Solving (iii)

$2 (8a - 5b) + 3 (5a - 12)$

Open bracket

$2 (8a - 5b) + 3 (5a - 12) = 16a -10b + 15a - 36$

Collect like terms

$2 (8a - 5b) + 3 (5a - 12) = 16a+ 15a -10b - 36$

$2 (8a - 5b) + 3 (5a - 12) = 31a -10b - 36$

Solving (iv)

$3 (y - 3) + ( 8 - 6y + x)$

Open bracket

$3 (y - 3) + ( 8 - 6y + x) = 3y - 9 + 8 - 6y + x$

Collect like terms

$3 (y - 3) + ( 8 - 6y + x) = 3y - 6y + x- 9 + 8$

$3 (y - 3) + ( 8 - 6y + x) = -3y + x-1$

Solving (v):

$a (a - 2b) + b (b + 2a - c)$

Open bracket

$a (a - 2b) + b (b + 2a - c) =a^2 - 2ab + b^2 + 2ab - bc$

Collect like terms

$a (a - 2b) + b (b + 2a - c) =a^2 + 2ab- 2ab + b^2 - bc$

$a (a - 2b) + b (b + 2a - c) =a^2 + b^2 - bc$

Solving (vi)

$5 (x - y + z) + (4x + 3y)$

Open brackets

$5 (x - y + z) + (4x + 3y) =5x - 5y +5z+4x +3y$

Collect like terms

$5 (x - y + z) + (4x + 3y) =5x +4x +3y- 5y +5z$

$5 (x - y + z) + (4x + 3y) =9x - 2y +5z$

6 0

2 years ago

1. Find f(3) for the function below. f(x) = 4^x

Wewaii [24]

Answer:

Step-by-step explanation:

f(x) = 4^x,

When x = 3,

=> f(3) = 4^3

= 4 * 4 * 4

= 64

7 0

2 years ago

Read 2 more answers

The highest point in North Carolina is Mt. Mitchell, with a height of 6,684 feet. Write the height of Mt. Mitchell as an integer

vlada-n [284]

6.5 ik cuz I took da test ekdiksbwhwiaowb wwiiweb eieiebejeiebe woke. E

7 0

2 years ago