Answer: [tex][Q - R] + [S - T]=10m+7n-14[/tex]
Step-by-step explanation:
Given : [tex]Q = 7m + 3n[/tex],
[tex]R = 11 -2m[/tex],
[tex]S = n + 5[/tex], and
[tex]T = -m - 3n + 8[/tex]
Now , [tex]Q-R= 7m + 3n-(11 - 2m)[/tex]
[tex]Q-R= 7m +3n-11+2m[/tex] [ ∵ (-)(+)=(-) and (-)(-)=(+)]
[Note : when -1 is outside the parenthesis it indicates that -1 should be multiplied with each of the terms present inside the parenthesis .]
[tex]Q-R= 9m +3n-11[/tex] [Combine like terms.]
[tex]S-T=n + 5-(-m - 3n + 8)[/tex]
[tex]S-T=n + 5+m+3n-8[/tex] [ ∵ (-)(+)=(-) and (-)(-)=(+)]
[tex]S-T=4n +m-3[/tex] [Combine like terms.]
Now, [tex][Q - R] + [S - T]=[9m +3n-11]+[4n +m-3][/tex]
[tex]=9m +3n-11+4n+m-3[/tex]
[tex]=10m+7n-14[/tex] [combine like terms]
Hence, [tex][Q - R] + [S - T]=10m+7n-14[/tex]
