Solve x+3y=6 and 4x-6y=6 by elimination . PLEASE SHOW WORK !!!

What is the ratio for cos B ?

TiliK225 [7]

Answer:

3/5

Step-by-step explanation:

Cos(B) = adjacent/hypotenuse

Cos(B) = 48/80 = 6/10

Cos(B) = 3/5 or 0.6

7 0

3 years ago

a rectangle is 8cm longer then it is wide, and it’s area is 153cm^2. Find the dimensions of the rectangle.

Stolb23 [73]

Answer:

Width of 9cm and length of 17cm.

Step-by-step explanation:

To calculate an area of a rectangle, use the formula A=l*w. We know the length is 8cm longer than the width. So l = 8 + w. So the area is A= (8+w)*w.

We also know the area is 153. Substitute this value for A and solve.

$153 = (8+w)(w)\\153 = 8w+w^2\\w^2+8w-153 = 0$

To solve the quadratic, use the quadratic formula:

$\frac{-b+/-\sqrt{b^2-4ac} }{2a}$

Here a=1, b=8 and c=-153.

$w=\frac{-b+/-\sqrt{b^2-4ac} }{2a} \\w=\frac{-8+/-\sqrt{8^2-4(1)(-153)} }{2(1)} \\w=\frac{-8+/-\sqrt{64+612} }{2} \\w=\frac{-8+/-\sqrt{676} }{2} \\w=\frac{-8+/-26 }{2} \\w=\frac{-8+26 }{2}=\frac{18}{2}=9 \\and\\w=\frac{-8-26 }{2} =\frac{-34}{2}=-17$

Since w=9 or w=-17, substitute this value for w in l= 8+w to find l.

l = 8+9 = 17

or

l=8+-17 = -9

Since length cannot be positive, it must be l=17 and w=9.

8 0

3 years ago

A repair bill for your car is $553. The parts cost $265. The labor cost is $48 per hour. Write and solve an equation to find the

Lilit [14]

Answer:

6 hours

Step-by-step explanation:

Let the labor hours be x.

The bill comprises of parts cost plus labor cost. Labor cost is hours times the cost per hour. Then we have equation:

265 + 48x = 553
48x = 553 - 265
48x = 288
x = 288/48
x= 6

So the answer is 6 hours.

4 0

3 years ago

Find dy/dx x^3+y^3=18xy

tatyana61 [14]

Differentiate both sides of the equation.ddx(x3+y3)=ddx(18xy)ddx(x3+y3)=ddx(18xy)Differentiate the left side of the equation.Tap for fewer steps...By the Sum Rule, the derivative of x3+y3x3+y3 with respect to xx is ddx[x3]+ddx[y3]ddx[x3]+ddx[y3].ddx[x3]+ddx[y3]ddx[x3]+ddx[y3]Differentiate using the Power Rule which states that ddx[xn]ddx[xn] is nxn−1nxn-1 where n=3n=3.3x2+ddx[y3]3x2+ddx[y3]Evaluate ddx[y3]ddx[y3].Tap for more steps...3x2+3y2ddx[y]3x2+3y2ddx[y]Differentiate the right side of the equation.Tap for fewer steps...Since 1818 is constant with respect to xx, the derivative of 18xy18xy with respect to xx is 18ddx[xy]18ddx[xy].18ddx[xy]18ddx[xy]Differentiate using the Product Rule which states that ddx[f(x)g(x)]ddx[f(x)g(x)] is f(x)ddx[g(x)]+g(x)ddx[f(x)]f(x)ddx[g(x)]+g(x)ddx[f(x)] where f(x)=xf(x)=x and g(x)=yg(x)=y.18(xddx[y]+yddx[x])18(xddx[y]+yddx[x])Rewrite ddx[y]ddx[y] as ddx[y]ddx[y].18(xddx[y]+yddx[x])18(xddx[y]+yddx[x])Differentiate using the Power Rule which states that ddx[xn]ddx[xn] is nxn−1nxn-1 where n=1n=1.18(xddx[y]+y⋅1)18(xddx[y]+y⋅1)Multiply yy by 11 to get yy.18(xddx[y]+y)18(xddx[y]+y)Simplify.Tap for more steps...18xddx[y]+18y18xddx[y]+18yReform the equation by setting the left side equal to the right side.3x2+3y2y'=18xy'+18y3x2+3y2y′=18xy′+18ySince 18xy'18xy′ contains the variable to solve for, move it to the left side of the equation by subtracting 18xy'18xy′ from both sides.3x2+3y2y'−18xy'=18y3x2+3y2y′-18xy′=18ySince 3x23x2 does not contain the variable to solve for, move it to the right side of the equation by subtracting 3x23x2 from both sides.3y2y'−18xy'=−3x2+18y3y2y′-18xy′=-3x2+18yFactor 3y'3y′ out of 3y2y'−18xy'3y2y′-18xy′.Tap for fewer steps...Factor 3y'3y′ out of 3y2y'3y2y′.3y'(y2)−18xy'=−3x2+18y3y′(y2)-18xy′=-3x2+18yFactor 3y'3y′ out of −18xy'-18xy′.3y'(y2)+3y'(−6x)=−3x2+18y3y′(y2)+3y′(-6x)=-3x2+18yFactor 3y'3y′ out of 3y'y2+3y'(−6x)3y′y2+3y′(-6x).3y'(y2−6x)=−3x2+18y3y′(y2-6x)=-3x2+18yDivide each term by y2−6xy2-6x and simplify.Tap for fewer steps...Divide each term in 3y'(y2−6x)=−3x2+18y3y′(y2-6x)=-3x2+18y by y2−6xy2-6x.3y'(y2−6x)y2−6x=−3x2y2−6x+18yy2−6x3y′(y2-6x)y2-6x=-3x2y2-6x+18yy2-6xReduce the expression by cancelling the common factors.Tap for more steps...3y'=−3x2y2−6x+18yy2−6x3y′=-3x2y2-6x+18yy2-6xSimplify the right side of the equation.Tap for more steps...3y'=−3(x2−6y)y2−6x3y′=-3(x2-6y)y2-6xDivide each term by 33 and simplify.Tap for fewer steps...Divide each term in 3y'=−3(x2−6y)y2−6x3y′=-3(x2-6y)y2-6x by 33.3y'3=−3(x2−6y)y2−6x33y′3=-3(x2-6y)y2-6x3Reduce the expression by cancelling the common factors.Tap for more steps...y'=−3(x2−6y)y2−6x3y′=-3(x2-6y)y2-6x3Simplify the right side of the equation.Tap for more steps...y'=−x2−6yy2−6xy′=-x2-6yy2-6xReplace y'y′ with dydxdydx.dydx=−x2−6yy2−6x

6 0

3 years ago

Find X. See image below.

Nitella [24]

written answer in the picture

4 0

2 years ago

Read 2 more answers