Răspuns :
(9x9-m-8x4):7=4
(9x9-m-8x4)=7x4
(9x9-m-8x4)=28
(81-m-32)=28
81-m=28+32
81-m=60
m=81-60
m=21
(9x9-m-8x4)=7x4
(9x9-m-8x4)=28
(81-m-32)=28
81-m=28+32
81-m=60
m=81-60
m=21