Pls help I’m begging u I asked like 3 times already

Sherina wrote and solved the equation. x-56=230 x-56-56=230-56 x=174 what was sherina’s error? sherina’s work is correct. sherina only needed to subtract 56 from 230. sherina made a subtraction error when subtracting 56 from 230. sherina should have added 56 to both sides of the equation.

Simplify 24÷(-2)(3)+7 a. -29 b. 3 c. 11

Math i have no idea how to do a and b