Question

求这道计算题的过程及答案

Answer 1

<img class="ikqb_img" src="https://iknow-pic.cdn.bcebos.com/0df3d7ca7bcb0a462719e1616463f6246b60afab?x-bce-process=image/resize,m_lfit,w_450,h_600,limit_1" data-ik-caption-text="x-y=1
2x+y=8 "/>
<p class="ikqb_image_caption" data-ik-caption-text="x-y=1
2x+y=8 ">x-y=1
2x+y=8
x-y=1 变为x＝y＋1，
代入下式，
2x+y=8 变为2（y+1）+y＝8
2y＋2+y＝8
3y＝8-2＝6
y＝6/3=2
x＝y+1＝2+1＝3

Answer 2

x=3

y=2

Answer 3

x-y=1 ①
2x+y=8 ②
首先将①式+②式，把y消掉，将二元一次方程化为一元一次方程求解x
3x=9
x=3
将x=3带入①式求解y
3-y=1
y=2

Answer 4

Answer 5