Excel. Number sum, the number is the text format. How to become conventional. And then sum? Text can not sum!

Excel. Number sum, the number is the text format. How to become conventional. And then sum? Text can not sum!

You can set the cell format and change the format to a number. If you can't change it, you can change the formula to the following when you sum, that is, add two horizontal lines in front of the area to convert the text to a number
=SUMPRODUCT(--A1:A3)
Or & nbsp; & nbsp; this is an array formula, and you need to press Ctrl + Shift + enter & nbsp
=SUM(--A1:A3)

Seeking: formula expression and summation formula of arithmetic sequence and arithmetic sequence in mathematics!: -)

Arithmetic sequence:
an=a1+(n-1)d
Sn=n(a1+an)/2
Equal ratio sequence:
an=a1q^(n-1)
Sn=a1(1-q^n)/(1-q)

There are 135 students in a certain grade who work in three groups. The ratio of the first group to the second group is 2:3, and the ratio of the second group to the third group is 6:5
Give me the formula of the system of equations of degree 2~

Suppose there are x people in group A, y people in group B, and 135-x-y people in group C
Equations:
x/y=2/3
y/(135-x-y)=6/5
The solution is as follows
x＝36
y＝54
135－x－y＝45

Rookie, don't answer! Table misleads me, mathematical genius!
1. The same absolute value as the end of 1790 degrees, the smallest angle is - 10 degrees. 2. If three lines intersect each other, if they are not coplanar, then the number of intersection points is 1

The first 360x5 = 1800, that is to say, 1790 less than 10 degrees is right for the second one