Can someone please help me

Find the midpoint m of z1=(8+5i) and z2=(12+3i)

What would be the reasons for lines 3 and 4? a. addition property; subtraction property b. addition property; solve c. substitution property; subtraction property d. substitution property; prove

Jorge wants to determine the enlarged dimensions of a digital photo to be used as wallpaper on his computer screen. the original photo was 800 pixels wide by 600 pixels high. the new photo will be 1,260 pixels wide. what will the new height be?