Can someone explain how to solve this please?

51

step-by-step explanation:

73-22=51 the   mass number minus the amount of protons gives you the amount of neutrons

the expression (1.26)2t reveals the approximate rate of increases in the number of plants semiannually.

hope this : )

the aswere is the one with all 8's and the second one is with the 10,8 and 6

step-by-step explanation:

2. angles qrt and qst both measures 156 degrees.

step-by-step explanation:  

we have been given a diagram of a circle and we are told that measure of arc qvt is 156 degrees.  

we can see from our given diagram that angle qrt and angle qst subtends to arc qvt.

since we know that angles subtended by the same arc at the circumference are always equal.

by angle subtended by same arc theorem, measure of angle qrt and angle qst will be equal to the measure of arc qvt.

therefore, angles qrt and qst both measures 156 degrees and 2nd statement is the correct choice.