9.
which equations are equivalent?
iii.
1.
12x +30-10x +4= 40
40=2(15-x)+4
2(6x +15-5x) +4=40
ii.
a.
i & ii
c.
i & iii
ii & iii
d.
none of the equations are equivalent

  C.  I & III

Step-by-step explanation:

I simplifies to ...

  2(6x +15 -5x) +4 = 40

  12x +30 -10x +4 = 40

  2x +34 = 40

__

II simplifies to ...

  40 = 2(15 -x) +4

  40 = 30 -2x +4

  40 = -2x +34 . . . . . . not equivalent to I (sign of x-term is different)

__

III simplifies to ...

  12x +30 -10x +4 = 40

  2x +34 = 40 . . . . . . equivalent to I

___

I & III are equivalent

-4

step-by-step explanation:

do 6-10=

if u need it to be negative.

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116