Question

629-(333-у)=459
(357-(у-281))+112=402
13*х-9*х-16=27-7
19980:(7*х-15)=54

Answer 1

629-333+у=459
у=459-629+333
у=163

(357-(у-281))+112=402
(357-у+281)+112=402
-у+638+112=402
-у=402-112-638
-у=-348
у=348

13х-9х-16=27-7
13х-9х=27-7+16
4х=36
х= 36:4
х=9

19980:(7х-15)=54
19980:54=7х-15
370=7х-15
-7х=-385
7х=385
х=385:7
х=55