plan an investigation that karen and her mom can conduct to test if copper sulfur pyrite or calcium will result in a new substance if they were mixed with water

Abcd is a parallelogram find the valuse of x

Jada has a meal in a restaurant she adds up the prices listed on the menu for everything they ordered and gets a subtotal of $42.00. when the check comes, it says they also need to pay $3.99 in sales tax. what percentage of the subtotal is the sales tax

Find the magnitude, correct to two decimal places, made by each of the following with positive direction of the x axis a) y= x the answer is 45° but i don’t know how