Question

 800-(90*х+17)=423, 240:(у:15)-18=42 

Answer 1

 800-(90*х+17)=423
90х+17=800-423-17
90х360
х=360/90
х=4

240:(у:15)-18=42
240:(у:15)=42+18
240:(у:15)=60
у:15=240:60
у:15=4
у=4*15
у=60

Answer 2

To solve the first equation, we need to isolate the variable "x" by performing operations on both sides of the equation until "x" is by itself.

800 - (90*x + 17) = 423

800 - 90*x - 17 = 423 (distribute the negative sign)

780 - 90*x = 423 (combine like terms)

-90*x = -357 (subtract 780 from both sides)

x = 3.9667 (divide both sides by -90)

Therefore, x is approximately equal to 3.9667.

To solve the second equation, we need to first simplify the expression inside the parentheses by performing the division.

240:(у/15) - 18 = 42

16*(у/15) - 18 = 42 (simplify the division)

16*(у/15) = 60 (add 18 to both sides)

(16/15)*у = 60 (multiply both sides by 15/16)

у = 62.5 (divide both sides by 16/15)

Therefore, у is equal to 62.5.