Find the value of b such that the system of equations - 15x-9y= 13
10x + by= 13
does not have a solution.

What is the solution to the equation 9^(x+1) =27

One number is 4 less than 3 times a second number. if 3 more than two times the first number is decreased by 2 times the second number, the result is 11. use the substitution method. what is the first number?

Which of these angles are supplementary? a. 100o and 90o b. 78o and 102o c. 54o and 146o d. 12o and 78o