How would you use base ten blocks to model: 4\ \div\ 84 ÷ 8

Circle a has center of (2,3) and a radius of 5 and circle b has a center of (1,4) and a radius of 10. what steps will show that circle a is similar to circle b 1) dilate circle a by a scale factor of 2 2) translate circle a using the rule (x+1,y-1) 3) rotate circle a 180 degrees about the center 4) reflect circle a over the y-axis

For what values of a is the sum of the fractions 2a−1 / 4 and a−1 /3 positive?

Give another definition of variability and explain how it can be calculated.