Question

Układ równań:
a)
y - 7000x = 3000
8000x - y = 4000

Answer 1

a)
y-7000x=3000
8000x-y=4000

y=3000+7000x
8000x-y=4000

y=3000+7000x
8000x-(3000+7000x)=4000

y=3000+7000x
8000x-3000-7000x=4000

y=3000+7000x
1000x=4000+3000

y=3000+7000x
1000x=7000 /:1000

y=3000+7000x
x=7

y=3000+7000*7
x=7

y=3000+49000
x=7

y=52000
x=7