bob is twice as old as alice at the moment in 4 years time their total age they will be 71 what is alice's age now?

7. if the value of x varies directly with the value of y, and x = 3 when y = 21. what is the valu y, and x = 3 when y = 21. what is the value of x when y = 105?

Determine the difference: 3.2 × 1010 – 1.1 × 1010. write your answer in scientific notation.

Atriangular field has sides of lengths 21, 39, and 41 yd. find the largest angle. (round your answer to the nearest degree.)