Sam sold half as many as Odel.
That means Odel sold twice as many as Sam.

Let x = number of pizzas sold by Sam.
Then Odel sold 2x.
Altogether they sold 126

x + 2x = 126

3x = 126

x = 42

Since x is the number of pizzas sold by Sam, that is our answer.

Answer: Sam sold 42 pizzas.

4 0

3 years ago

Find symmetric equations for the line of intersection of the planes. z = 4x − y − 13, z = 6x + 5y − 13

MArishka [77]

The intersection line of two planes is the cross product of the normal vectors of the two planes.

p1: z=4x-y-13 => 4x-y-z=13
p2: z=6x+5y-13 => 6x+5y-z=13
The corresponding normal vectors are:
n1=<4,-1,-1>
n2=<6,5,-1>

The direction vector of the intersection line is the cross product of the two normals,
vl=
i j k
4 -1 -1
6 5 -1
=<1+5, -6+4, 20+6>
=<6,-2,26>
We simplify the vector by reducing its length by half, i.e.
vl=<3,-1,13>

To find the equation of the line, we need to find a point on the intersection line.
Equate z: 4x-y-13=6x+5y-13 => 2x+6y=0 => x+3y=0.
If x=0, then y=0, z=-13 => line passes through (0,0,-13)

Proceed to find the equation of the line:
L: (0,0,-13)+t(3,-1,13)
Convert to symmetric form:
$\frac{x-0}{3}=\frac{y-0}{-1}=\frac{z-(-13)}{13}$
=>
$\frac{x}{3}=\frac{-y}{1}=\frac{z+13}{13}$

3 0

3 years ago