In scientific notation, what is the sum of 2.3 times 10^{-3} and 5.4 times 10^{-4}?
a. 2.84 times 10^{-3}
b. 5.63 times 10^{-3}
c. 7.7 times 10^{-7}
d. 12.42 times 10^{-12}

Aswim teacher sells lesson packages. the best deal has the highest ratio of lessons to total cost.swim lesson packagesnumber of lessons total cost$10$4010 1 $8015$80which package is the best deal? l lesson for $105 lessons for $4010 lessons for $8015 lessons for $80mark this and returnsave and exit

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.

Solve 2x+y=3 x+y=5 in substitution method