1 3x +15+7x=10x+15=10×4+15=40+15=55
2 48+12y-5y=48+7y=48+7×2=48+14=62
3 6x+8x+28=14x+28=14×3+28=42+28=70
4 9y+12y+10=21y+10=21×7+10=147+10=157
1 3x +15+7x=10x+15=10×4+15=40+15=55
2 48+12y-5y=48+7y=48+7×2=48+14=62
3 6x+8x+28=14x+28=14×3+28=42+28=70
4 9y+12y+10=21y+10=21×7+10=147+10=157