Please I need help. Solve for b and c using addition or substitution

To solve by addition or subtraction, you need to coefficients of either term to be the same (or negatives of each other).

If you multiply 0.3 by 11, you get 3.3, which will allow you to cancel out the c terms.

159 b + 3.3 c  =  1000   --->  leave this alone   --->   159 b + 3.3 c  =  1000

 2.3 b + 0.3 c  =  18      --->   times 11     --->          25.3 b + 3.3 c  =  198

Subtract down the columns:                                  133.7 b            =  802

Divide by 133.7:                                                                    b   =  5.9985  (approximately)

Substitute this value into either equation:  2.3 b + 0.3 ( 5.9985)  =  18      --->   b  =  14.011 (approximately)

b = 5.9985 and c = 14.0115

Thank you both. I've had so much confusion trying to solve this one. I appreciate your help!