Bài 1:
\(a.79.56+56.13-92.54\)
\(=56\left(79+13\right)-92.54\)
\(=56.92-92.54\)
\(=92\left(56-54\right)\)
\(=92.2\)
\(=184\)
1.
\(b.67.35-35.59-8.15\)
\(=35\left(67-59\right)-8.15\)
\(=35.8-8.15\)
\(=8\left(35-15\right)\)
\(=8.20\)
\(=160\)
1
\(c.43.51+43.28-79.16-79.17\)
\(=43\left(51+28\right)-79\left(16+17\right)\)
\(=43.79-79.33\)
\(=79\left(43-33\right)\)
\(=79.10\)
\(=790\)
Bài 2:
\(a.140-120:x=125\)
\(120:x=140-125\)
\(120:x=15\)
\(x=120:15\)
\(x=8\)
2
\(b.180:x+37=73\)
\(180:x=73-37\)
\(180:x=36\)
\(x=180:36\)
\(x=5\)
2
\(c.137-130:\left(x-13\right)=37.3\)
\(137-130:\left(x-13\right)=\frac{37}{3}\)
\(130:\left(x-13\right)=137-\frac{37}{3}\)
\(130:\left(x-13\right)=\frac{374}{3}\)
\(x-13=130:\frac{374}{3}\)
\(x-13=\frac{195}{187}\)
\(x=\frac{195}{187}+13\)
\(x=\frac{5057}{187}\)
1:
a.
=56.(79+13)-92.54
=56.92-92.54
=92.(56-54)
=92.2
=184
b.
=35.(67-59)-8.15
=35.8-8.15
=8.(35-15)
=8.20
=160
c.
=43.(51+28)-79.(16-17)
=43.79-79. (-1)
=79.(43 -1
