Miracle,
You asked -
The difference between six times the first number and 6 times the second number is negative twelve. The first number is nine times the second number minus ten. What are the two numbers?
Answer: You have to read carefully to parse the algebraic expressions from the word problem. First I'm going to define the variables:
x - first number
y - is the second number
Reading the first sentence "6 times the first number" is 6x, and 6 times the second number is 6y, the difference between them is 6x-6y is equal to -12. Here is the equation:
6x-6y=-12
Now reading the second sentence. The first number x is 9 times the second number 9y minus 10 or 9y-10. Here is the equation
x = 9y-10
Now we have two linear equations with two unknowns we can solve by graphing, substitution or addition methods. I'm going to use substitution, from the second equation
x=9y-10 I'm going to plug it into the first equation 6x-6y=-12
6(9y-10)-6y=-12; now use the distributive property and collect like terms
54y-60-6y=-12; collect like terms; add 60 to both sides to isolate the term with the variable
48y=48; divide each side by 48
y = 1; now that we know y put into the second equation and solve for x
x = 9(1)-10 = 9-10 = -1
Can you check to see if my answers are correct?
Regards,
Ray