Albert said:$A=$$\square$1 $\square$2 $\square$3$\square$4 $\square$5$\square$6 $\square$7 $\square$8 $\square$9
randomly fill in each blank with eather $"+"$ or $"-"$ ,
(1) prove $A$ can not be $12$
(2) find the total numbers to make $A=21$
To find the total numbers to make A=21, you can use basic algebraic equations and solve for the unknown variables. In this case, you would need to find two numbers that add up to 21.
There are multiple combinations of numbers that can add up to 21. Some examples include 10+11, 8+13, or 5+16. The possibilities are endless!
No, the instructions specify to find "total numbers," which typically refers to whole numbers. Decimals are not whole numbers, so they cannot be used to make A=21.
No, there is no specific order in which the numbers should be added. As long as the sum of the numbers is 21, the order does not matter.
Yes, negative numbers can be used to make A=21. For example, -5 + 26 = 21. As long as the sum is 21, any combination of numbers can be used.