## Andy C.'s Resources

They are complementary and add up to 90   x + 2x+54 = 90   3x + 54 = 90   3x = 36   x=12   12 and 78

Yes   3x + 3 - 4y + 4  = 13   5x + 10 - 2y - 6 = 0       3x - 4y + 7 = 13 5x - 2y +4 = 0   3x - 4y = 6 5x - 2y = -4     -7x = 14   x=-2 y=-3   CHECK: 3(-2...

X+Y=144   X/5 = Y   X + X/5 = 144   5X + X = 720   6X = 720   X=120   Y=24

w(3w-8) = 3.5   3w^2 - 8w - 3.5 = 0   30w^2 - 80w - 35 = 0   6w^2 - 16w - 7 = 0   w = [16 +or- sqrt ( 256 + 4*6*7)]/12   (4/3) +or- sqrt(256 + 126)/12   (4/3) +or- sqrt( 382)/12   (4/3)...

3x <= 6  OR   x>=0   X<=2 or x>=0

180 km = 180 000 meters = 18 000 000 cm   18 000 000 ------------    500 000   = 36

27 + 15 = 42

X-Y = 9 ---> X = Y+9   5Y = 3X+7   5Y = 3(Y+9) + 7   5Y = 3Y + 27 + 7   5Y = 3Y + 34   2Y = 34   Y=17 X=26

7/8   So if each pizza is cut into 8 slices, each boy gets 7 slices because 7x8=56     7/8

R = O - 10   O = 2R   r = 2r - 10   0 = r - 10   r=10 O=20

Ax + 3x - Bx = 5   x(A+3-B) = 5   x = 5/(A+3-B)

1st odd integer is X 2nd odd integer is X+2 3rd off integer is X+4   X + 2(x+2) + 3(x+4) = 58   x + 2x + 4 + 3x + 12 = 58 6x + 16 = 58 6x = 42 x=7   7.9,11   7 + 2x9 + 3x11= 7+18+33...

4 x 4 = 16   4.2  x   4.2 = 17.64   The difference of the area is 1.64

K is how much longer the LENGTH is from the width.    X + X + x+k + x + k = 96   4x + 2k = 96    4x = 96 - 2k    x = (96-2k)/4       = 24 - (1/2)k     So K is how...

3/40 = ? / 140   40 * ? = 3 * 140   40 * ? = 420   4 * ? = 42   2 * ? = 21   ? = 21/2   10 or 11

20% of \$35 = 20/100 * 35 = 20/100 * 35/1 =  700/100 = 7   \$7 off

10x-14> =0   10x> =14   x> =14/10 = 7/5   x> =7/5   [7/5, infinity)

The least common denominator is 18   7/9   vs    5/6    <---- multiplies 7/9 * 2/2 and 5/6 * 3/3   14/18   vs 15/18   So 7/9 = 14/18 < 15/18 = 5/6     The difference is 1/18

11 - -4 = 11 + 4 = 15